I need advice asap!!!

Ok so me and my SO have been dating for almost 2 months and he is best friends with my ex that I was on and off with last year. Me and my ex have always been close and we both care about each other. Recently I've been having dreams where I end up leaving my SO for my ex and this dream happens almost every single night. Currently my ex is in a relationship that is on unstable ground but I don't want to do anything to make it worse. I know that me and my ex always have had a better relationship when we just stay friends but I still want to try again even though I don't wanna ruin what I have with my current SO. Please help!!!