Bloating, Fullness, Constipation, Pain. Prescribed Omeprazole. Cure?

Hi I hope someone could help me I m 21 and I m in alot of pain I been to all different doctors and hospitals I have bad adomen pain for 5months I had different types of pain some of the pain got better and the other pains got worse I have been going through the worse 5 months of extreme pain doctors tell me all of my tests comeback negative nothing bleeding and no cancer thank god but why am I having pain they told me I had ulcers and gastris abput 3months ago and now I still feel the gastris pain I feel like I m suffering alot they did xrays and all different tests and stilll told me to take the gastris medication omeprazloe I been taking it for months and I don t know why but this month I been having heavy bloating fullness unable to move bowels so I went back to the hospital 8hours and they said maybe its ibs but they have not been able to tell me what s wrong with me I m in alot pain I don t know what to eat anymore and I feel like I m going to die pleaseeee help I m scared and I feel like doctors are not being serious about this what can cure gastris and bad constipation cuz I think I got all of thiis because they didn t know what I have and they got me constipated.