Sometimes, it's less that a trans woman becomes gay when she transitions, and more that she already was homosexual in her attraction before she transitioned. A lot of transfeminine sapphics have described being attracted to women in a gay way before they identified as a woman. The same goes for straight transfems who didn't feel like their attraction to men was gay, but got lumped in as gay because of their assigned gender.
It should also be said that "attraction changes" that happen from hormones are often more absolute than relative based on gender. It's more like someone who wasn't attracted to men before suddenly is, or that someone who didn't feel sexual attraction to anyone now does. Sometimes it's just that you're more comfortable being who you want to be, and sometimes it's your preferences actually changing. It redefines your relationship with your body, identity, and sexuality change in ways you don't expect.
Any words of affirmation I could say probably wouldn't help, nor would suggesting how you could improve things. What you sound like you're asking for here is to be heard; for someone to acknowledge you; to acknowledge your pain. I want to do that, but I also don't want to cause distress to the people who browse here who also might not be doing well. I'll leave the comment up for about an hour, and then I'm removing your post.
I don't know if there are any spaces on here to vent about these issues, so if you want to talk with someone, you can message me. The messages won't be private, but they won't be broadcast onto this community for all to see which is what I'm most concerned about.
Yay!!!!!!!!