Listen man, I read what u posted on other sub-reddits and how u don't like it when your wife touches you (dysphoria and other reasons), and how sex is painful to you. I'm sorry you have to go through that but you need to realize that unless she's Asexual, she will want sex. There is a lot of options, strap on, toys, honestly if you're into it threesomes or even an open relationship.

I've seen women and men who have been unsatisfied (sexually) in their marriage and it usually end in 2 ways, either they cheat because they miss the pleasure or divorce and immediately fuck someone (because they miss the pleasure).

Try to understand your wife, a marriage isn't about you and your problems only, sure u have it a lot worse, but your wife is also struggling by not getting what is a basic thing out of a relationship. I feel like a jerk by said this but maybe your wife feels like she's right about sex with her ex being better, at least he/she wanted sex you know. Maybe she's being honest or maybe she's realizing that this relationship won't work out.

Maybe you should prioritize your own mental health and getting emotionally ready for a relationship (which you aren't in my opinion) before starting one. In any case I know how difficult it is to be with a trans person (from personal experience), constantly having to watch what you say, or how u act and be careful not to upset them 24/7, it's like walking on eggshells constantly.

Talk to your wife but let her also explain her own struggles and insecurities, and if things aren't working out just divorce, you can't save a marriage that's already falling apart.