It is most likely panic attacks. my friend had weed induced panic attack to the point of shaking and weird heart rythms and breathing. He was forced to quit. he then switched to Glass (fuckin dumbass) but he did go to the hospital for those panic attacks. Weed sets off a chemically imbalanced brains. If you are a manic depressive or if you have bipolar disorder it can affect you good and help, or it can affect you bad and give you worsened symptoms of the disorder.