I don't think you're having a psychotic break. You probably have dissociated from the pain for the time being, your mind protecting itself and trying to give you a break from pain which was getting to be too much. You seem to be aware that your brain is doing this to protect itself and of who you really are, just divorced for now from feeling like yourself. I think this is a necessary and not particularly unhealthy way to manage your overwhelming feelings in the moment. You'll feel like yourself eventually, when you can handle it.

If you're not in therapy or seeing a psychiatrist, I hope you'll consider doing these things. They might offer you some longer-term solutions.