I'm right there with you, except in my case, he was the bad guy and I'm the one left in pieces. I hate the effect that this is having on my school work. I had a major exam yesterday, and I couldn't even bring myself to study -- I binge watched House of Cards all week (I normally never watch TV) and I very likely failed my exam.
I'm sorry that you're going through a hard time. Just know that you're not alone, and that things WILL get better in time.