Nobody here can diagnose you, but it definitely sounds sounds as if some derealization/depersonalization is going on.

Generally a psychotic disorder has multiple symptoms rather than solely feeling unreal. I'm not specialized in the human brain/emotions, but I think that the break from reality caused from psychosis is characterized by symptoms such as: disorganized speech/behavior, delusions, & hallucinations. You don't seem to have any of these from what you have said & clearly stated that you didn't have hallucinations nor delusions. Also I think I've read that these feelings can be caused by anxiety.

But like I said: nobody here can diagnose you & I am in no way a specialist.

Maybe you should go to the dissociation forum on here & ask them about this.

Hope that you are feeling better asap!