Generally paranoid, it's not that uncommon.
weed induced paranoia - Google Search
Speaking for myself, while I used a considerable amount of marijuana in the seventies I can't say I recall experiencing any feelings of paranoia -- either while under the influence or not. But I do recall some others mentioning paranoid feelings after (or during) smoking pot. As I recall it was said jokingly by them, but your comment about quitting entirely suggests something quite serious. If you would describe some of the paranoid affect you experienced I would be seriously interested in reading about it.
Everything I'm able to Google up thus far suggests this paranoid experience affects some users but not all and those who do report on the experience suggest it is temporary and superficial rather than serious and disturbing.
If your experience was sufficient to cause total abstinence I would call that serious.
Do you know anyone else who was similarly affected?