Hi Emma, I am coming a little late into this thread, and I am a lot older than you.
I did not really know that I was transgender when I was about your age, but I am also intersex, and my psychologist felt that I had my menopause at about this time ( I am biologically part female and part male). This trans thing, and the menopause, and a chronic pain situation made me very angry, and I destroyed my very happy marriage of almost 40 years. Looking back now, I would have given up any trans idea if I could have saved my marriage. I am alone since then, and feel very lonesome.
Yes, I have lots of friends, because becoming a woman made my emotions more gentle and people really love to be with me, but I am still lonesome. When the evening comes, everybody leaves me, and I am alone! I don't miss sex, but I miss cuddling in bed, having skin contact, hearing nice and freindly words, and feeling loving touches. I am alone and lonesome! Every night!
I am a woman, or at lest pretty much a woman, but I am a lonesome woman!
Because of my experience, I can only advise you to do everything you can to keep your marriage going, even if you have to give up to become a woman, because for me it was better to almost be a man but not be alone, than being a woman who is alone every night of the year!