I need help, I'm in LOVE with BFF and ex brother-in-law!!! BIG DILEMMA!?

OK. I was the girlfriend of a guy for 4 months. He left me, and moved in with a new girlfriend in a matter of 5 months or so... Then, his brother and I became BFF's and we shared everything together, we hung out almost everyday, without feeling anything for each other, until one night, that he kissed me. Then, we started to become closer as a pair, and we started having and it seemed like I was on cloud nine. We started arguing, like a normal couple, but he was scared to talk to his brother to get his approval of the relationship, but he was too scared and didn't wanna do it. We drifted a bit apart, but we still hung out, and we didn't PDA because we were like, PROHIBITED. No one could know what was happening, cause the talk would start. Then, one night, he told me that he was a bit, just a bit attracted to a friend of mine, and that pissed me off. I maybe over-reacted, but it still hurt my feelings. He made me choose what to do with the situation, and I decided not to be his friend or his "girlfriend" anymore. WHAT CAN I DO? I love him, and he loves me too, but it's driving me CRAZY!!!