Hello everyone,
Well, I'm sure that a lot of what I plan to ask is already out there, and it's not that I'm too lazy to search for it; but the idea of HRT is a very fresh one to me, and the information on it is unfortunately greatly diluted by random articles that don't always have an entirely factual base. So, I here I am, asking the same bunch of questions that I'm sure many of you have answered time and time again, and hopefully will continue to do so, for the sake of us who are inexperienced.
I don't feel like I can accurately give depth and meaning behind my questions without having some kind of context behind what I'm saying; and with a life changing decision such as this, I can only attempt to give it context by presenting a shallow view of my entire, short, life. As such, this is going to be a fairly long post, but I will be leaving a tl;dr down below if you wish to skip past the wall of text.
I'm a 22 year old male currently, and I don't have the best long-term memory; but I'd say that my general desire to be female has been around for as long as I've been able to tell the difference between girls and boys. I didn't exactly develop my social abilities as soon as most children, this was because I was born with too much fluid in my ears, making me both permanantly in pain, and deaf until the problem was fixed, therefore while around the age of 3-4, I had to go to speech lessons, which resulted in me being fairly well spoken. I felt like I was on the wrong side of some line, but I wasn't sure what it was. I played with boyish toys and didn't mind that, but I also enjoyed being cute and doing cute things.
By grade 2 I had kissed a boy for the first time and immediately told my parents I was gay that day. They corrected me and told me that a play kiss doesn't make me gay; I accepted their explanation and I felt quite embarrassed, leading me to the decision to keep all future such curiosities to myself rather than openly discuss them with my family. Another thing that I started at that age was martial arts, something that I have kept doing for the rest of my left. Later on in primary school, my grades had started to struggle, and most of my teachers were telling my parents that I was always daydreaming in class, because I was. So, I was put onto Ritalin, after which my grades immediately improved to straight distinctions. But it also made me constantly tired, exhausted and unhappy, and twisted my personality from what was once an energetic and extroverted child to that of an introvert that questioned himself every time he considered speaking, and for the most part, practically stopped speaking entirely. This was also when I first started having vivid suicidal thoughts, which have continued throughout my life. At this stage of my life I was still not openly discussing any of my problems with anyone. Puberty also came around near the end of primary school, along with acne.
Once I started Highschool I stopped ADD medications, and also stopped martial arts(Only to start with another a year later). I had a fairly average highschool life, I wasn't very fond of my peers at first, but as the years went on I got to pick my own subjects and ended up in the classes with slightly more decent people in them. My acne also continued through highschool, generally destroying my self confidence at all times, and leaving me fairly depressed in general. Without any ADD medication, I was free to daydream as much as I wanted, and most of this daydreaming was me thinking of how wonderful life could have been if I had been born a girl. But I never considered acting on this frustration. Another thing I started with in highschool and continue to this day is MMO gaming in general, in which I will always identify as, and roleplay as a female.
After highschool I immediately went to university. I still had acne and I felt miserable just being around other people because of how uncomfortable I felt. I generally missed most of my lectures to sit in the clubroom of the club I was in or just stayed at home. I still wanted to be a girl, but I was by then very used denying the thoughts about it. Due to still not being on ADD medication, and also being incable of concentrating on anything I didn't find interesting, I ended up failing math twice and leaving the university, despite doing well in my actual subjects of choice.
I then moved onto a different college, it was a fairly terrible place, but there were no subjects unrelated to my field of study, and I was free to learn at my own pace, so I thrived despite the actual difficulty of the course being far above average. During this time my skin had become even worse, and I was repeatedly having to go through week long anti-biotic courses to cure outbreaks of Cellulitis caused by my acne. I was sick of it, so I asked my gp for something that would last. I ended up doing a six month course of Isotretinoin. This was a big leap for me, it came with a bunch of risks and my experience with ritalin left me cautious of anything that had a chance of altering my personality, but I was so tired of feeling terrible because of how uncomfortable I felt in my own body. The risk paid off, and now I have almost no problems with acne compared to the past, it gave a major boost to my confidence, my comfort in my own body and it gave me a slightly more open minded view on medications that mess with hormones.
It's been almost a year since then. In the past year I have gotten to become more involved with the BDSM scene, thanks to my newfound confidence; finally getting to act out some of the phantasies that I thought I would never get to feel. In that time I have discovered that I am definitely pansexual, and that I definitely have no actual attraction to the idea of regular straight sex. I will always want to be the submissive person in a relationship, and I will never want to be on top. I want to be the 'girl' in the relationship.
More recently, I have noticed the exponentially increasing amount of increadibly sexy, cute MtF trans on various image boards... and I am just so damn jealous of every one of them. I'm already regretting that I didn't find out that HRT could actually be so effective before I hit puberty. Or that I had talked about my problems and have been sent to a therapist that could have started me on them. But that's all water under the bridge now.
tl;dr
I'm soon to turn 23, I want to give HRT a shot. I finish my current degree in 2018, and plan to move as soon as I'm done either way, so I'm not worried about any kind of inconvenience with family or friends, because I can just avoid making it their problem. I don't plan to change my name, or legal gender at this point. I desperately want this, but I also don't want to end up going down this path if I already have no hope of being a 'passable' female. I don't expect to ever wear a swimsuit, or be walkway material, but I don't want to end up being plainly a guy with boobs. I just want to be feminine, to match what I am inside.
Are there any especially good resources on:
Pros and risks of HRT
The exact chemistry by which HRT works?
I've seen some threads mentioning low dosage HRT, would there be any advantage to low dosage in my situation?
Is the whole corset during HRT thing really effective for reshaping the rib cage?
Am I too old at 22? Would I be ruining my chances even further if I waited another year or two?
Does it actually look like I have any chances of being 'passable', brutal honesty appreciated :c (Will attach a body pic, just send me a private message for face picture.)

I've seen HRT durations ranging from a few months to a few years, how long can I be on it without having to worry about noticable changes occuring? (i.e. if I want to start it just before finishing college)
What kind of formal therapy is it best to seek out in order to be prescribed HRT?
Edit:
-Anyone know if my previous course of Isotretinoin would cause problems with other hormone medication?
Not sure if I'm missing anything really, this is pretty much the first time I'm coming across a decision that I'm not entirely concluding based on meditation and self-reflection; so I'm not very good at seeking help.