AM i CRAZY or Just in LOVE?

Why cant I get over my ex. WE were only together four like six months but he cheated on me and I found out; so we broke up. The thing is we continue about every two months to sleep together. HE says he loves me, but thats all i can get out of him. He now has moved to Boston and wont speak to me; not even on yahoo messenger or myspace. This is normal for him; he disappears and then reappears. Last night i had too much to drink and called his moms house repeatedly; trying to find out how to get ahold of him. WHATS wrong with me?