What do I do?

I'm in love with him. And he's in love with me. After 10 months of 'just friends' and trying to move on with other people. And we're back to the same position as we've been twice before. We're in love, and I know that should be amazing. But we're both too scared to try again, incase we get hurt. Twice, we've been together. And it didn't work. Hell, I don't even know why. Of course neither of us want to run the risk again. But it's so damn hard knowing I could have him. And knowing that something's stopping us. I'm more than willing to take the chance. I'd give everything I have for this. I just wish I knew how to tell him that. What am I supposed to do?