Been over a year-can't shake feelings for my ex of 10 years. She has moved on-why can't I do the same?

She has spent our year apart basically sowing her wild oats with MAJOR scumbags and now says she's got a boyfriend. I'm not perfect, but outside of me, her taste in dudes is horrific!!! I've tried everything--literally, with little/no success. I'm really losing it--need help thanks...