breakup

Recently i broke up with my boyfriend who was emotionally abusive and extremely controlling. Why do i feel like i made a mistake by leaving him if he made me so unhappy? Shouldn’t i be happy to have gotten out of the relationship? I feel crazy for missing the person who hurt me the most and made me feel like i was nothing. Any tips on how to stop feeling like this?? I know I shouldn’t miss him but i cant help it.