While a family member did drugs, I never did because I understood if I found the magic drug that made the pain go away, it could greatly delay my transition. There is a lot to fear in the transition. For me, I think there were three points in my transition that were terrifying. They were coming out to my parents, the first time I left my apartment as myself and GCS. I kept my life simple so I avoided coming out to a wife and loss of my job didn't result in much pressure because I didn't have others relying on me for support.
You are in a difficult position because you need to face all these things to find happiness but the drugs are keeping you from doing so. I am not sure how you were able to get off drugs before but if you were in a treatment program, you need to return to it and while there you need to face this truth as well. I don't know if you are strong enough to face this by your self but therapy and possible the others in your life can help.
The one good bit of news I can give you is after you face each obstacle, you will discover that they were not as difficult as you expected. When I told my parents, my stomach was knotted for three days but I was done with it and I still had a family. Leaving my apartment became easer each time I did it. With surgery, all the fear was gone as soon as I woke up from surgery. I have lived many years free of fear, discomfort with myself and as myself. That can be your future as well but you have to decide that it's the most important thing in the world for you to have.