Could you go permanently insane from lsd?

Highly unlikely: There is an entity called hallucinogen persistent induced perception disorder, but while it was believed in the 60s and 70s to be common, further evaluation showed that most people with these symptoms after using hallucinogenic drugs were people with underlying thought disorders - early schizophrenia, schizoaffective disorders etc. "insanity" is actually a legal, and not a medical term.