I also did it 2-4 times a week for a couple of years in the mid 90's. I was a real weirdo. I used to preach all of this consciousness expanding stuff. I almost ran off to India once. Glad I didn't.

I never had real flashbacks. However, for years after I still hallucinated, but it was a constant thing. Nothing major, just the typical one where the walls and everything look like curtains.

I went a bit psychotic towards the end, but that wasn't the LSD. It was all the others . . . .