How am I supposed to move on

I’ve been with my kids father ever since I was 17 I’m 21 in dec he was basically my first love my first everything we got 3 kids together and I’m currently pregnant with #4 I left him yesterday because he lies about me talks bad about me he never really cared about my feelings he has hurt me in so many ways in the past year I’m so attached to him I wanted to move on so many times but couldn’t I just miss him so much I love him I want him back I’m so helpless how can I move on please I don’t want to go through this pain while pregnant please give me advice.