Lost and heartbroken

My ex girlfriend and I were together for 5 years. We had been living together for the whole relationship. 3 months ago she told me she didn't want to be with me anymore. I didn't want to accept it and tried to work things out.

A few weeks ago she told me to leave the house and threatened to call the cops if I didn't. I had to quit my job and move back to the state I was previously living in before our relationship.

Found out after I left that she had been talking to another man for those 3 months, maybe even longer. I cared about her more than anyone I've ever been with. She has blocked me on social media, phone, etc. Was told that she has already started a relationship with this other man.

These few weeks have been very difficult, have been trying lots of self care. However, even after eating healthy, exercising, trying to keep my mind occupied, I still think about her.

I'm struggling to not break down and give up on everything on nearly a daily basis.