Is it normal to feel this after a break up

So me and my boyfriend broke up Monday.. today would have only been 3 months. I cared for him but, honestly knew that he probably wasn't the one to be with at this time.. we had a lot of differences. Now I feel relieved and happy... yes I miss him a bit. The question I have is whenever I try to think about having a relationship with someone else.. it just feels weird. I can only see him. I can only imagine kissing him or cuddling with him. When I have the thoughts of someone else I get anxious and sad. I felt so comfortable and safe with him and the thought of another man scares me ( I had abusive men in my past) he was the first one I guess I wasn't afraid of. I've never felt this way after a break up. Is this a normal thing?