Whats Wrong with me ?

Hey! i had a terrible experience with pot, this happened 2 months back when i freaked out because one of my friend came up with a topic (when we were smoking pot) regarding another friend of mine in an accident! It freaked me out, i was not aware of anything around me and i was screaming! I started to panic very badly! i was CONVINCING myself that it was an overdose and i was going to die! it was the worst i had ever experienced! i was tripping my head out! it stopped after like 7 hours of intense tripping! but what i want to know is even after 2 months of quitting weed!! ! Whenever i think about it i feel like its coming back and i am sooo scared of that terrible cycle starting all over again! i still get these acute panic attacks when i start to think of it! and trust me i have tried all possible ways to get these thoughts out of my head! but they dont seem to go! i am really scared of it happening again! thats why i haven laid a finger on a joint in 2 months, i feel it may erupt if i smoke again cause i am alll the time panicked of it happening again! SOMEBODY PLEASE TELL ME HOW TO GET RID OF THESE ACUTE PANIC ATTACKS WHICH FREAK ME OUT ! AND WHY ARE THEY STILL THERE WHEN I HAVE STOPPED SMOKING POT!