abdominal / pelvic pain and extremely nauseated

Two weeks (12 days to be exact) ago while I was in bed I began to feel nauseated but it only lasted about 1-2 hours. The following night it came back and lasted well in to the next day. A couple days after I began having rib and back pain and then pretty bad abdominal / pelvic pain. I finally decided to go to the doctor eight days after all of this started and he said I had a bladder infection. The antibiotics he prescribed worked fine and the abdominal / back / rib pain went away.

Other symptoms have started to develop though. I started to feel horrible heartburn and had constipation. The nausea "comes and goes" and is usually present only at night when I'm in bed. I get this throbbing feeling in my stomach that keeps me awake for hours.

Last night I felt extremely nauseated and every time I fell asleep I instantly woke up and had to catch my breath - almost as if I stopped breathing for a moment (though I'm not sure of course).


Today, which is four days after I saw the first doctor, I went to an urgent care center and the doctor there said I was fine and told me to take 20mg of pepcid everyday for a month. He also told me to eat foods that are high in fiber to help my bowel movement. After taking a urine sample he said I no longer had the bladder infection and he also tested my blood sugar level, which was fine. I forgot to tell him about the incident the night before but when I got home I didn't really think anything of it because I was confident that I would soon be better.

The pepcid helped my heartburn dramatically, though I can still kind of feel it. The thing that worries me now is a have that throbbing in my stomach, especially when I'm in bed and also my breathing seems to become too shallow when I'm really tired, along with waking up the moment after I fall asleep to catch my breath. And about an hour ago I noticed that there's pain on the right side of my lower back.

I'm terrified to fall asleep now and I have chest pain (I'm thinking it could me from the heartburn). What should I do? I really feel that all of these problems are an indication to something else going on inside my stomach but when I told the urgent care doctor he said that he doubted that my infection and heartburn / nausea were related.

I feel as if my symptoms are going to get worse but I don't know what to do. I'm afraid if I go to another doctor then he'll just tell me nothings wrong. Should I go to the hospital for this? I think that they need to check out my stomach via ultrasound but I'm not sure if they would without a good reason...

I'm really scared. Please give me any advice or info!