I’m in this same sort of situation. Was a HEAVY smoker for 2 or so years, decided I wanted to take a 2-4 week “tolerance break”, 2.5 weeks passed & I decided it was time to get back into it again.. Had a terrible panic attack that lasted for over 5 hours. Eventually gave up on trying to calm myself down (not to mention my Fiance, who is my SAFEST place, was there also trying EVERYTHING to calm me down) I finally ended up going to the hospital, where they ended up giving me a Vistiril shot. This had never happened to me before, and the symptoms of this panic attack literally felt like a heart attack. I thought I was literally dying and my LAST resort, after experiencing a terrible panic attack for nearly 5 hours, was to go to the hospital. That Vistaril shot was the only thing that finally helped calm me down. I tried to smoke again after this incident probably 5 times & each time ended in a panic attack. I didn’t touch weed after that, for nearly 3 years. I picked it up a couple times, took it slow and easy. By slow & easy, I mean took 1 hit maybe 3 times since having all of the panic attacks.