I need to wallow

On December 7 I broke up with my ex boyfriend and we had a very toxic relationship. Monday I found out that he has a new girl and I don't know why but that hurts me so bad. I am not fully recovered from the break up and this is making it worse, I'm crying every day and I think about it every day but is not my place to feel this way because he has the right to move on. What it hurts the most is how fast he moved on and how I'm here crying because I went through so much to be ending up like this. I hope you guys understand this feeling, like I gave everything for this guy. 2 years and a half together and no matter if I remove him from social media or throw away all the things he gave me, it hurts because I am not over him, and it kills me. I'm a mess, I can't focus on school things aren't going well. I'm so sick of this feeling, of feeling hurt for no reason but damn it I have feelings towards him and they won't go away. I hope this pain is worth it at the end because I can't no more. Any advice on how to keep it positive and not think about it?