HI.
Your Problem is Pain in abdomen and gas formation. due to this i feel tried,serve headache & sleep issue for a long time..
If the USG and CT are normal, we can think this as a problem of irritable bowel syndrome/ infection of the intestines.
A proper course of antibiotic must have been given to you by this time.
It looks you need to look into your dietary habits-> there must be something in food that is not suitable for your intestines, identify and stop completely.
Secondly you may have to change your lifestyle- the
anxiety is one of the most important factors in problems like you have.
Thirdly add probiotics avai;able as Pre-pro / Darolac, Activated
charcoal tablets like
gasex, avoid late nights, you should get the complete and sound sleep, No stress/ worries/ anxiety-> change the situation around you...
All this will help you to have a proper betterment.
At Maximum you can undergo
colonoscopy to rule out any organic problem