Your interests have diverged, it seems. You want out, you said. Your problem now is how to get out comfortably enough, I suppose. It will likely be difficult. I don't think you're overreacting - your sexual interests have simply diverged. And sex seems more important to him than the relationship, ie you two. To me this underscores the need to get out, since evidently you can't resolve this with him. (IE you felt the need to discuss it here rather than solely with him.)