We can't give you a diagnosis because we're not Drs. But, we can try our best to help and support you.
Yes, it does sound to me like you were having a very severe panic attack when you went to the hospital. I'm take it they did testing on your heart and all was well with it? I see that you're only 20 so the odds of you having a heart attack are almost non existent.
THC can cause panic attacks in some people. It sounds pretty strange because it really calms most people down. Some, it can do just the opposite though.
You already know that you need to stop the THC, caffeine and Adderall.Any of these can cause panic attacks and anxiety.
What you may be going through is worrying about having another panic attack. It can become a vicious cycle. You have your first one and worry so much about having another one that it happens.
I would highly recommend seeing your Dr for the follow up tests and if everything comes back fine then think about therapy. It will help you learn how to deal with your anxiety and learn techniques that will help if you feel a panic attack coming on.
It's a good thing to learn about all this while you're only 20 - and it's good to see that you can pick out certain lifestyle "indicators" that could contribute to what you're going through.
I'm not a DR, but from my own experiences, it can be difficult to differentiate between panic attacks, anxiety attacks and low blood sugar. All of these things should be looked at.
Also learn about seizure thresholds - things that "lower" a seizure threshold means, in short, it's easier to have a seizure. Alcohol withdrawal, excess caffeine, THC for some people, and a variety of medications can lower seizure threshold....
Warning signs for seizures... fear/panic, tingling, strange feelings, etc..
So, no need to panic, just back off the questionable stuff you don't have to take and learn about the way your body works. Better to know ahead of time than be caught thinking "oops, I wish I had known...."