Hysterectomy is a pretty big deal for women. It actually marks the end of reproductive ability, and for some women, the end of a sexual life, too (though this need not happen). After a hysterectomy, a woman needs, more than ever, a kind, supportive husband who has read a lot about the subject. You admit that you're kind of distant, which needs to change. I strongly suggest marital counseling. If your wife will not accompany you, go alone. You will learn a great deal, and it might either save your marriage or at least show you what may have gone wrong.
In my opinion, your worries are not unfounded. I have heard similar stories from other women (or their husbands/partners) after hysterectomy. It really messes with our hormones. I lost my loving feelings for my husband after my (unwarranted) hysterectomy. I don't even have the strong maternal feelings for my children. It makes me very sad and I held onto a lot of anger for a long time (I am still angry with my former gynecologist/surgeon). My surgery did dredge up some resentment for the "bumps in the road" over our marriage. I also put some guilt on my husband for the hysterectomy because I was scammed by my doctor and my husband did not see through it either.
I went through a bit of counseling to deal with the betrayal by my gynecologist. I still don't have the strong bond for my husband and children but I have let go of blaming my husband and myself for not seeing through my gynecologist's scare tactics.
I hope you and your wife can work through this and come out stronger in the end.