What do you think I should do?

Okay, So I have a boyfriend as of right now... a few weeks ago he told me he wanted to "take a break" and he asked me what I thought and I told him I didn't want to.. but he kept bugging me about it so I finally said yes, well the day after that he asked me back out so I said yes then that night he said he wanted to "take a break" and at that point I was like whatever... well we didn't talk for a few days, and I started liking this other guy (andrew). (yes, he has told me he likes me too) and andrew was really nice and sweet to me. But when my ex boyfriend asked me back a couple of days later I'd already told andrew that I liked him. I told my ex that I would have to think about it.... I said yes to my ex, but I told him that when we weren't together I started liking another guy... It's been a couple of weeks now I'm in trying to figure out what to do... and no matter what I do... I can't seem to get andrew out of my head! And I've had dreams about him and everything /: what should I do?