Is it normal?

My child’s father and I’ve been broken up for almost 7 months . He’s moved on already and is with someone else. I cant seem to move on . Like the thought of dating feels a little wrong and i feel guilty because my kids are both under two. I don’t really have the time . I want to get over him and move on but i don’t think I’m ready. I always think about him 🤦🏾‍♀️. I would never get back with him because he’s a serial cheater. Is it normal to feel like this?