I had a similar experience. I took psylocibin a few times, but after the last one I started getting panic attacks and feeling derealization quite often. This led to negative recurring thoughts and I felt really bad for a while. Got better after a year of cognitive behavioral therapy and six months taking a light dosage of antidepressants. Routine exercises and zen meditation helped tremendously as well. Get help, it is possible. Your brain can heal itself with your help.