Trouble in Paradise?

My fiancee and I have been together for a good while now, and before we really got together and a little bit after, he was really enthusiastic about sex and playing with me and pleasing me, but now he just? He's completely not into it. And I don't mean he just acts that way, he says it. I wasn't sexual before I got with him due to trauma, but I finally opened up and got comfortable enough with him to get into the scene. I've talked to him about it and I know it's not really my fault, but it makes me feel disgusted with myself, like I should've just stayed away from all of it. It's honestly kind of embarrassing wanting to do anything with him now.. I... Don't really know what to do about it. Neither of us wants to separate, but it's really taking an emotional and mental toll on me, and I have no idea how to try fixing anything, or if I even can.