I wouldn't say my situation was exactly the same as yours, but I did feel that transitioning was impossible and hopelessly unrealistic since I believed I would never pass as a woman anyway.
Eventually I just couldn't take it anymore. Transition or not, I couldn't remain as I was forever. I finally came out to my wife and therapist, told the whole truth about my lifelong hidden struggles to both of them, and spoke with an endocrinologist at the local lgbt clinic. I was scared out of my mind, because full transition at this point in my life would be very messy (married, kids, career, etc.). The endocrinologist had a lot of good points about the manageability of HRT. Some outward feminization might be unavoidable no matter how low the dosage, but I should be able to pass as a man if I need to for as long as I need. So, I took a deep breath and jumped into HRT.
And...I wish I had done it years sooner! Emotionally and mentally I began to feel improvement within hours of my first dose (I take pills, not patches or injections). I am coming up on 4 weeks on HRT and I haven't felt this stable and calm emotionally and mentally in decades. At least since before puberty. I now have no doubts that my brain was meant to run on female hormone balance. Even at the low dose that the endocrinologist started me at, I feel so much better that I find it hard to believe that I used to function successfully without it.
For the first time in my life, gender dysphoria is manageable. It's still there, and it still bothers me many times every day, but I haven't felt suicidal even a single day since starting HRT.
As for changes in sexual orientation, I have not experienced that and don't believe it is very common.
MTF HRT does two things: it feminizes the body and it provides a female hormone balance for your brain and nervous system. The first part can be managed through dosage, but where most people find the biggest improvement in quality of life is in what HRT does for the brain, emotions, and mind. I personally would try HRT if I were in your shoes and had access to a good lgbt endocrinologist. It is completely reversible in the first few months no matter how aggressive the dosing, which should be plenty of time to figure out if it helps or not.