Last Week My Stomach Started Bothering Me Thought It Was

Last week my stomach started bothering me thought it was my ulcer I was taking Pepto for 3 days because I became constipated. Then I got real bloated. I started taking gas x didn't work. Then last night I took milk of magnesium. I went to the bathroom my stomach bloats up and down and now I am having terrible cramps. What should I do. I have been trying to walk, drink water, sprite and eat crackers. I have taken hot baths and laid with heating pad.