Relationship advice? any suggestions appreciated?

I hate to come to yahoo answers with this. After two months of dating my boyfriend and I had sex. Yea I know it's early and all that but I wanted to and I honestly have no regrets. Two days after I went out of town for the summer. After being gone for 3 weeks, I felt like he wasn't treating me right and I broke up with him. A few days later, we reconciled and he asked for me to take him back. I waited a few days and I told him yes. He then started telling me how he wanted to wait til I get back so he could be sure. He went on to tell me that he feels like our relationship is built on sex, that the mental part of our relationship is gone, and that he feels like we're basically just best friends with benefits. Honestly I thought you're suppose to be with your best friend who you're attracted to. I really want to save my relationship. I feel like the distance and me always wanting/ talking about sex is what's messing up our relationship. I'm willing to change that but I'm not sure how to go about it. I don't know what to do. Help?