sadly in love with the wrong guy.

I need some advice. I'm in love with this guy I've been talking to since the 7th grade- I'm in 11th now. And we hung out multiple times this summer.i stayed the night at his house twice. And we would always say I love you. But now he has a girl and has twins on the way. He texts me saying he missed me and wished it was different but he had to block my number because of her. I saw him yesterday in town. He looks good. I just can't seem to let him go as easily as he let me go. I need some advice on how to let him go.