There may be some wild, outside chance that you really do have a serious medical problem (however you sound young). But you seem to acknowledge yourself that what is happening are likely panic attacks. And so if you can figure out something that you can do to avoid them, I say go for it. Because I know from my own limited experience with panic attacks that they can feel intensely uncomfortable (I've had a handful of them myself over the years after smoking certain types of pot).

Next, you needn't wonder about what is happening when you feel like crap directly after quitting smoking. Everyone feels horrible. Although 6-7 cigs per day is a pretty mild habit, and so I'd guess your symptoms are probably more psychological rather than resulting from nicotine withdrawal. But no, no one ever dies from quitting smoking. They only die when they don't quit smoking. And people usually (although not always) start to feel better after about 3 to 4 weeks of being cigarette free. So try to hang in there a bit longer before you make any final judgements on this. Good luck!