Your breathing problems are probably caused by anxiety. Do you feel anxious/stressed when you smoke weed? It's not uncommon.


As for the pain in your neck, do you currently have soft tissue damage or some other form of injury? I personally have damage to my neck, back, and spine in general and find that if I smoke too much weed it REALLY makes the pain worse for me (if I smoke moderaly, it still helps the pain). I don't know why this is, I've searched google inside out and found no evidence of weed causing pain, you're the first person to be in the same boat as me. Whatever the cause, good luck to you man.