Crying to have sex

I have been married for going on 7 years. We are both 26. Yes i know it was way too young to get married and no we don't have kids. But thats the problem i want to start a family but i cant do it alone. My husband has no sex drive...at all. We have sex maybe once a month of I'm lucky. I've tried everything but only when i cry and get upset will he have sex with me. I think to shut me up. I don't know what else to do. It makes me feel gross and unattractive but he swears its not that. I've asked if he is getting somewhere else and the answer is no. What do I do now?