How to get over him

marii • Fl , 23

I’ve been single for 4 months from a year relationship. We just fell apart but now he has a girlfriend and i still think about him. I’ve tried to get back with him but he just didn’t want me anymore. How can i get over him ? i still think and miss him so much he wants nothing to do with me and he’s already moved on. He was my first love and real relationship so its hard to move on. Help please