Yes, some of this is going to be grief. Anytime we lose someone or something, like a marriage, no matter who's fault it is we have to grieve. If it is possible try to see a counselor. You need help to work through this. You are not missing "him" your missing what you wanted him to be but wasn't. You might also want to write an unsent letter. Right everything you want say to him, then tear it into tiny pieces and say goodbye. It' helped me get past my guilt and hurt after my divorce. Good luck. Glad you are in a safe place.