Any time we walk away from things in out life that we are attached to rather it be for the best or not, we will always look back on them and question if we made the tight decision or not. It's the nature o the beast. How ever the best way to over come this is simply to edify your decision to leave it every time you question it. When you start to wonder what if, just tell your self No I left that behind and remember why you did. Good luck. I hope this helps.