What Causes Heart Palpitations And Stomach Cramping After An Injury?

Skipped heart beats since Christmas. Drank too much over Christmas and had big fall out which was stressful. Just before Christmas had accident where fell jolted and had whiplash. Could I have hernia? Could I have damaged something? Not stressed now and not drinking but come on worse in evening after food. Do get some cramps around stomach which does stick out abit. Doctor says can only get hernia if stabbed? Walk loads and ok when exercise about two stone overweight.