Oh wow, I know what you mean about mary jane and the panic attacks, I had quit smoking it at 30 then tried it a few times about 5 years later... The last time I was in hell. My mind went nuts and got stuck dwelling on how worthless I (and everything else) was for about an hour or so, I actually feared that I was going to kill myself. Which is an unusual thing for me.
I can only suggest diluting the potency or buying the weakest mj you can get (and for sure tell your dr.)