What Causes Abdominal Pain,dizziness And Frequent Urination In Men?

Dear Doctor,I am a 24 year old Male. 4 days ago I started experiencing a stomach ache. Sometimes it around the belly button and at times under the rib cage. I feel bloated, nauseous and dizzy at times. My bowel movements has somewhat been altered, (increased but not diarrhea) and I am urinating more often. (No pain when urinating). My last meal prior to the onset of the stomach ache 4 days ago was with eggs and a glass of milk and I also had one baked oyster. The oyster tasted a bit off and I regret I did not spit it out. Please advise.