stomach protrusion/extreme pain

I take an exorbant amount of pain meds and I am aware of the fact that is causes me to be constipated, but I do go on a regular basis and it is a lot. I recently went to the hospital and they took an x-ray and said I was extremely constipated, prior to that I had gone to my local Dr and they did an ultra-sound on me and said there was nothing. Well we all know our body the best and last week I just couldn't take the pain anymore with my stomach so I went to my Dr,( first time due to insurance change) He put me on ativan, omerprazole Dr 40mg 1x a day, and hydroxyzine pam 25 mg 4x's a day. It seems to be helping my stomach but when I eat anything, like, I just ate an orange and I am in severe pain. My Dr said he wanted to see me back in 10 days to see how I am doing. I know if I have ulcers I have to change my diet, which oranges are one of my favorite things but, I know I have to give them up. What I am worried about it my stomach protruding out excessively, and I have shortness of breath no matter what I do. When I went to the hospital, the e.r. dr told me I should go get an upper GI and a colonoscopy? What else can you suggest to help with my problem, as I don't know how much longer I can endure this pain. Its right under my breast bones and travels down to the right side. Please if you know of any suggestions I would be greatfull. Could the protrusion be from swelling from ulcers? Or could it possibly be cancer? I have blood work done on a reg basis due to the medicine I take, would my white blood cells be elevated if I had cancer? Thanks for any information you can give, like I said I am in severe pain, always! Sincerely, Melissa