What Causes Pain Near Navel After Masturbation?

Hi Doctor, I have a peculier problem. After I masturbate I get some pain on left side of umbilical, bad gas problems after some time. The next morning when I woke up I feel severe headache on one side usually left side and top of my brain, I see some swelling on back side of left brain. This pain lasts for almost 10 to 12 hrs, I dont feel like taking food during that time. If a painbalm is applied i get some white sticky substance from my nose and feels like a vomting at that time(may be acidity symptoms not sure, not diagnoised yet). I dont know whom to consult for these problems. Please advice. I am 28.