From the tone of your posts, it sounds to me like you already have enough roadblocks in your life, brought on by your own feelings about being forced to live as someone you're not. How it makes you feel about interacting with people, and forming connections.
Short of being practical, something I'm not super well known for. I'm going to suggest a few things, perhaps of a more esoteric nature.
First of all, I'm not sure that transition is the cause of the fears you have. It's a symptom, sure, but... hmm... I wonder if it's more a twofold fear of the unknown, and of losing control. What I mean by that is... your posts give a lot of importance to how other people will treat you or what they will think. What if they do this, or think that, or say the other? That unpredictability. Uncertainty. And the second part to that is a fear that these reactions are based on something you have very little control over. And can't get away from.
Knowing you're going to have to face something, and being afraid of it, is a different sort of apprehension than not knowing what you're going to face. When you know what's going to happen, you can prepare for it, and plan accordingly, and try to minimise the risk as much as you can. Fear of the unknown is a more pervasive, and invasive apprehension. It gives your mind free reign to come up with every possible spanner that can be thrown in the works of what you want to do.
Unfortunately it's also the most common fear that nearly all of us face at one time or another. I think mainly because we try and assimilate way too many variables in one go, and it all becomes a confusing mess of interrelated "What if's" that lead to the mind thinking "Oh hell no, this is just a house of cards just waiting to topple over." Perhaps a start on the path to dealing with this fear is to concentrate your attention more in the present, than the future. Take on the issues one at a time rather than trying to deal with everything at once and predict every possible outcome.
The fears you listed in your first post. Examine them one at a time.
Fear number one. The fear of being alone. You wonder if people would want anything to do with you once you transition. Something strikes me, when reading your second post. How you feel now, about socialising and interacting. You say that you find it difficult to socialise and impossible to date. So... forgive me if I'm missing something, but what exactly would be lost if you transitioned? As far as I can see, with the way you feel even thinking about transitioning, you're giving yourself the tools to feel better about yourself, to feel more secure in yourself, and a stronger base to actually go out and socialise with people, and maybe find that special someone.
Which makes me wonder, is it more the fear that the choice won't be yours to make? Like... you feel that at the moment, you have control over who you socialise with, or date. You could if you want to, but you don't want to because you feel uncomfortable playing a role you know isn't you. And that were that choice given to other people, they may reject you and there wouldn't be anything you could do about it. And that fear of rejection, and loss of control scares you more than the thought of being alone.
If so, that fear is the one you have to deal with. It's hard, I know. But a start is the realisation that everything you want to do, you want to do for yourself. Not to please other people, or to make other people like you. The realisation, and affirmation that you are doing it to make you feel better about yourself. Believe it or not, when you feel better about yourself, and start being more confident within yourself, this actually affects the way other people respond to you. Looks are less important than charisma and attitude. That's not to say it doesn't matter. It shouldn't matter, that's for sure. But feeling good about yourself has the added benefit that you want to make more of an effort in your appearance rather than just thinking "Yeah, whatever, I hate how I look so I don't care." And it can become a positive cycle which leads to some very unexpected results. People are more likely to care about you if you care about yourself. And if they reject you, then it may hurt, that's true, but that can be tempered somewhat by thinking whether you actually want to be associated with such superficial people, or whether you actually dodged a bullet and can find someone who isn't quite so shallow.
Also, think about it this way. What if you transition, find a bunch of friends, and even someone who loves you for who you are? How would it feel to know that you weren't being someone you're not? And that you can actually be yourself, live the way you want to live with them. Isn't that preferable to finding a bunch of folks who think they know you now but really don't have a clue, and hanging out with them just for the sake of saying you have people in your life? Rather than what if the worst happens... what if the best happens?
Fear number two. The only question I have to ask about this is... how good an actress are you? See the thing is, even if you don't change your outward appearance, people pick up on stuff. Not everyone is a knuckle-dragging gorilla that wouldn't know it was raining unless they got wet. And again, going by your second post, the way you feel now is already impacting your life. Enough for people who don't know, to suspect that something is wrong? I understand your fear. And... well, I can't say it's going to be okay. Because I've been in a situation where it was very not okay. But what I will say is this. You're already hiding from them, just... in a different way.
Fear number three. Firstly, if your family are unhappy about you doing this, then they're not going to tell you that you're going to be a supermodel. So perhaps it would be wise to take comments about whether you will or won't pass with a grain of salt. As much as I don't care for the word, I don't think passing is all about looks. As I've already mentioned, feeling more confident and happy within yourself is a big step towards being who you want to be, and wanting to express that in the best way you can. And sure, maybe some of it is your physical appearance, but hell women have a thousand and one tips and tricks to seemingly work magic on every part of your body. So I'm not at all sure it will be as hard as you think, or fear it will be.
Unfortunately, short of befriending Doc Brown, and somehow being able to snag a DeLorean to take you into the future, you can't know how it will turn out. But there are loads of things you can do to give yourself the best chance at being happy. Compared to the one thing you have to do to keep feeling this way... I'd say the balance is in going for it.
You won't be able to control other people and how they see you, but you will, perhaps for the first time, be able to control yourself and how you see you.
