what do I do??

 I'm with someone new..they treat me better and I deserve that but I had so much more chemistry with my ex it was so damn natural and felt like home being with him. This new guy  doesn't make me as happy and I don't feel like sparks...it's just not the same hype I got. He doesn't make me smile uncontrollably whenever we kiss like my ex. My ex is a family friend of mine btw but we've been talking for years. My ex & I still are attracted to each other but he doesn't want to commit as he lives 40 mins away. It felt so right being w him even tho He didn't treat me perfectly so how come I can't let go and just try to be happy w the new one?