Still in love with my ex but have a new bf

My ex and I dated for 2 1/2 years, even tho we were both very young, we experienced a lot. He slept over every week, and showered together and everything. I got pregnant at 16, and ended up having a miscarriage. It was really hard on me but I felt as tho he didn’t understand what I was going through bc he was never there for me, until he realized what happened later on, but it was too late, I had already broken up with him. Even tho I’ve dated people, I’m not be able to keep him out of my life. I would block him, and just end up unblocking him later on. 2 months ago, I met someone, who is amazing and has a beautiful heart but, my ex recently moved on and he had posted a pic with his new girl and I broke down. My worst fear was ever seeing him with someone new. I called him crying and he told me he’s not over me and no one will ever make him feel the way I make him feel, and I honestly just don’t know what to do