I can't get wet/turned on - what is wrong with me?

I am almost 23 years old, been with hubby for 3 years, had a baby almost 9 months ago. We never had any sex problems before we were married, and I had sex c-o-n-s-t-a-n-t-l-y before I was married, and now I can never get wet (I used to be perma-turned on) and I never even get turned on. I have put on some weight, so I could see that being an issue, and my husband and I have had a rough marriage so far, but occasionally I get very riled up and still don't get wet. And why is it only occasional that I get riled up at all? What are your thoughts? Has anything worked for you? I know I should see my OB/GYN so don't give me that advice, but let me know what you think. Or if you've been in the same/similar situation and what worked! Thanks in advance!