Obligatory Sex Since I Am Married???

I have been married for a while now. I take care of our home while my husband works. Most of the time I am exhausted after I put our daughter to bed. My husband (I assume like any other man) enjoys having sex all of the time. Sometimes (a lot of the time) I just don't want to. I don't get much pleasure, I don't feel as sexually attracted to him as I used to be (after all of his cheating last year), I do not feel obligated, and I'm tired. But he gets very upset when I will not have sex with him. He says I should have sex with him even if I don't feel like it since he takes good care of me and gets me just about everything that I want. What do you ladies think, should I be obligated to have sex with my husband, even if I don't want to????