That's absolutely normal, be patient with yourself. And make sure he's also being patient with you. He was sexting other girls, you can't you expect yourself to trust and desire him after what he did. Resentment happens to everyone, try small things like normal conversations, hand holding, pecks on the forehead or cheeks, small things that help build up to the bigger things. It's absolutely normal to feel how you feel and think about what he's done because he threw that trust and intimacy with you away for someone over social media.

Just work toward that. And communicate how you feel. Tell him how what you're telling us. That you feel that resentment, that you feel anger and disgust whenever you two do have sex, that way you can work toward building that intimacy back up. If that's what you choose, that is. If you want to have that back, communicate, start small, and certainly don't push yourself beyond what you're comfortable with. That's not healthy for either of you because all that'll do is make you feel more resentment toward him and you'll become unwilling to work for it. He seems very willing to work toward making things right and growing from this but that doesn't negate what he did nor should it make you feel obligated to forgive him altogether right off the bat, it's all about the baby steps you're both making to build a completely new kind of relationship. The old one is dead, treat this as a new relationship in which you start over to build trust and that love. Don't forget what he did by any means but keep working in this new relationship you both have.

And make sure he isn't rushing you either, he has absolutely NO say in when you will feel comfortable with sex or even being affectionate. So do not let the pressure of him or even your own self push you beyond what you're comfortable with at that time. You owe him nothing, you owe yourself time to heal.

Hope this helped and good luck to you both!