I fell really bad after taking LSD, will it improve?

I used to be a very, very, smart, active, energetic and healthy person. I took a strong dose of LSD 11 days ago and it was my only experience with drugs in my entire life. Since that I feel very bad. It's hard to think, my mind is heavy and foggy. My friends report I'm apathetic and I fell just like I've became a bit retarded. I also got some photophoby and a feeling of derealization sometimes, but I can deal with those. I know the drug is out of my system so...

What could have happened, medically talking?

Will my condition improve or I messed up a good brain forever?

[Dr Sharma]

Hi there. This must have been one of the bad trips, which LSD is infamous for. This happens due to the effect LSD has since it disables one’s judgement about the dose of street LSD . It can bring to surface buried and repressed unconscious material into conscious awareness. A bad trip occurs when the pleasurable effects of LSD turn into nasty and paranoid experience. They usually occur due to adverse environmental influence like noise, a larger dose than you have experienced before. If you are having a bad trip you could change the music to something light and familiar, change the surrounding to outside and quieter and non threatening environment. Confide in a reliable friend, concentrate on your breathing and divert your mind, may be by counting your breaths. Your anxiety is purely an effect of the drug, will pass, and won’t harm you. Self-reassurance works wonders. Take care.