Boy problems, of course... ?

My good friend & I met a week after I broke up with my boyfriend of two years. Needless to say, I wasn't ready to jump into any kind of relationship & he had his mind set on staying single & focusing on his career after a really volatile breakup months prior. We spoke for hours daily, supported each other, hung out & soon entrusted one another with some really personal information. After months, it was clear we were interested in one another as more than friends. Its been 8 months now, and we had our first argument. We got together to talk it through, and ended up having sex for the first time. Now I find myself falling for him, knowing well that he doesn't want to go that route right now. I guess what im asking, is what do I do now that im falling for my best friend knowing he's not emotionally available on that level?