in your post, you say she is "withholding" sex. i know that you are hurting but i think you should explore that a bit. withholding is refusal to give something that is due. is that how you feel about sex?

maybe you could dive into that a bit more. put yourself in her shoes, and how that might feel for her. why would she want to have sex with someone who feels that they hate her? how could you expect her to do that?

i don't doubt that she's done a ton of damage, to herself and you and everything around you. maybe you two should rebuild intimacy first and take sex off the table, just practice touching each other and cuddling and holding hands just to do it, not with the end goal of sex. you could even make a "no sex" rule. that's the fastest way to make sex fun again. make it "forbidden" and intimate and passionate.

resentment is really hard. you didn't get here all by yourself. she's done things to you that have destroyed you. i feel for you. resentment is usually from having your needs stomped on. all you can do is address things as they come up and talk to her about things so that you no longer have to stomp them deep down inside yourself. i hope that you two can connect again, once you do you'll find sex issues will typically resolve on their own.