I don't know if this post should be merged with the other one, but I'll try to break it down as much as possible.
LSD doesn't stay in your system for longer than a few days at most, actively, and there are trace amounts in your spinal fluid that are untapped. So, what you are experiencing now is not an acid comedown. However, judging from your first experience, there are a few things which may be happening:
You may have had an underlying condition, specifically generalized anxiety disorder, be 'brought out' or exacerbated by your bad trip. Within this may be some symptoms of PTSD, as any traumatic experience has the ability to semi permanently plant itself within your brain.
LSD is not a joke, it is a mind altering substance. After my first trip, which was incredibly profound, I felt the way I think be radically changed in the most positive of ways. It was scary at first though. To this day, I still ponder on the subject matter of my first trip. It opens your eyes. With such an intense experience will come intense afterthoughts and feelings.
However, you will be okay! The amazing thing about the human brain is that it is so malleable. It repairs itself and creates its own connections. Its a beautiful organ. And you will get better I promise. With time, reality will begin to slowly become more natural, and while you may still contemplate your first trip, you will feel like a normal person.
BUT, I highly highly suggest you give your brain a rest for awhile. Especially with psychoactive substances like marijuana. There is no fault in going to see a therapist either, as they will be able to diagnose and treat you a whole lot better than anyone on here. A health care professional would be a good place to go to first.
Also a small percentage of people experience Hallucination Persisting Perception Disorder (HPPD) after their first psychedelic experience. It's like russian roulette with psychedelics. This usually consists of CEV's and visual distortion that can impair some aspects of day to day functioning long after your trip has ended. It can also be treated.
A mild anti psychotic can stabilize your neurotransmitters, mood and perhaps vanquish the symptoms of HPPD and get you back on track, especially under the guidance of a health care professional. I suggest this route.
One last possibility is to trip on acid again, prepared, in a safe and comfortable set and setting. It sounds like your trip was unresolved and unfinished. Revisiting where you went too last time would be a good way to have a sound conclusion to your previous trip, and get (some) answers to the questions you were asking. I've found that psychedelics are immensely beneficial therapeutically. And often times bad trips can be learned and appreciated from. It's a lot about perception and how you're viewing your trip and in what light. Remember it's positive growth for your mental character.
But seriously, talk to your doctor. This is clearly bothering you. Best of luck man. We'll be here if you need us.
EDIT: Also, don't forget it is just a drug. If you don't want to place any meaning on it, you don't have too.
