Fuck dude, I’m so sorry. I’ve been where you are right now, like almost exactly where you are. Slight difference in my case was that was that she left when she got pregnant, married the other guy, and put his name on the birth certificate.
Maybe you don’t want to hear this, but to hell with her, okay? Even if she came back, you know what would happen? You’d spend all your time worried about her leaving again, you’d be miserable. And I can tell you from experience that moving on and finding someone else who appreciates you and is worth your loyalty will be the best thing that you ever did for yourself.
That aside, you need to fight for your right to see your daughter, okay? She needs you and if you let her mother keep her away from you, you’ll come to hate yourself for it. And you know what? The deck is stacked against you when it comes to that, you might not “win” but, once your daughter is old enough to start making her own choices about who she spends time with, knowing that you gave it your all will make all the difference in the world to her.