I have PTSD, and i take xanax at night just to get to sleep. my man, like my shit is insane. What i think is happening here is you are just getting into ur head too much. Exercise, dieting , and just living a purer life will help with the panic attacks. I know panic attacks, i dont wish them on my worst enemy, but i really think u r just getting into ur own head like i do sometimes. I even have to sit down and talk to someone to calm me down, but thats because mine is PTSD, not bc of marijuana use. I used to smoke weed everyday back like 6 or 7 years ago, but i just cant do it anymore bc i will get into my head and think about things and start doing the body checks like u said u do....i check my breathing, my temp, my reaction time, i even go through SLLS exercises and grounding exercises ....so for me, marijuana use was just a simple decision, and it just wasnt worth it. I do enjoy producing tho, and helping others enjoy the bud i produce....hope this helps man, i really do, anxiety sucks ass