Till Death Do We Part?

I got married a year and a half ago and sometimes I wonder if I did the right thing. I know that makes me sound like a horrible person, but that's really how I feel. My husband is an awesome man, but I have to ask myself...'Am I truly happy?' He bends over backwards to make me happy but yet I still feel like our marriage is missing something. Like last night for example, I chose sleep over sex, and that use to never happen. I don't know what's wrong with me. Mike is a great guy but I still find myself wondering if I can get better or get some one with more money and ambition. Money should not be that important to me, but it is. I love Mike, there is no doubt about that, I am just not sure this whole marriage thing is for me. Maybe I am too selfish to ever be married and have a family.