Sounds a lot like me, my friend. The psychadelics, the starting and stopping weed, thinking you have different disorders and always trying to figure it out. I've also had very random thoughts about hurting people or animals that just seem to appear out of no where. At first I thought I had social anxiety because I was fearful of people, but it's more or less the fact that my mind is always obessing over something negative that I couldn't keep a conversation going and felt awkward around people. That led me to be avoidant of people and I started researching and really thought I had Social Anxiety Disorder. I am more inclined to believe it might be some form of OCD now though.

I really identify with the last part where you said there have been times, even long periods where you were absolutely 100% fine with NO anxiety. I go through that too. My anxiety seems to come and go for months at a time and I can't figure out what triggers it or what makes it go away. I've been in and out of an "anxiety state" (I don't know what else to call it) more than 5 times now. I am also very fearful of losing my mind, losing my intelligence, etc. I am scared because even though I am very anxious right now, I am fairly confident it will go away, it just always seems to come back.

Sorry this probably doesn't help you man, just wanted you to know I feel a lot of the same things. We're in this together. If anyone can offer any insight please do