Normal thoughts - unless they get obsessive or turn into denial about how it wasn't that bad after all. Good thing about our thoughts is we can stop thinking them. Just stop. I had a habit of arguing with my stbx in my head. M1k3 here had some great advice - ask myself who am I talking to when I get into that cycle? It's become a great trick to acknowledge my crazy thoughts and stop them.
Break ups are hard, even when you know it is the right thing to do. Take good care of yourself!
~T