I made a mistake and now I am dating the best friend of the person I really like. Help!?

My ex girlfriend broke up with me a couple of months ago and sense then there's a girl who has completely been open about liking me. But after spending time with this girl I realized that I wasn't over my ex. In the mean time I begin to develop feelings for her best friend who is a guy. I started to date him because unlike the girl, he distracted me from my ex and I was able to feel like I could move on. But it wasn't long before I began to think and get upset about my ex again. And even worse.. I am not even sure if I am attracted to the guy. Sense I can't get over my ex regardless of who I'm dating I kind of want to be with the girl because I'm attracted to her at least. I don't know what to do.. Help!