My doctor told me I'm imagining my pain

I'm at my limit. Been dealing with abdominal pain for a month and got everything checked - they found nothing. Nothing in the gut, in the stomach. They tested blood and didn't even find any inflammation. Now this morning he sat there with his arms crossed saying he doesn't know what else to do and that I'm probably imagining the pain. I don't know what to do.

Symptoms:

  1. It started gastritis-like. Now the heartburn went away. For some time I got heartburn from water. Following my gastroscopy results it can't be gastritis.
  2. Every now and then my belly feels like it's filling up with something (gas?) and about to explode.
  3. I had taken pain meds, the strong ones too and they didn't help. The only position I feel like I could survive in is a shrimp-like position with hot water bottle and chamomile tea. Survive, not feeling well, survive.
  4. It is food related and at the same time not. I made a list of foods that were safe and tested them one by one. On some days they're safe. On other days they're not.

Yes I had attempted the mono cleanse. They don't have enough papayas in my region. Bananas only work in moderation, but not nearly enough to keep me going a day. Potatoes caused me pain.

Honestly I'm not sure about celery juice right not either because I always get diarrhea after drinking it. Not sure if that's the best idea when I'm already dealing with pain in the region.

Any help or heads up or *anything* would be greatly appreciated.