Let's talk step by step from what all issue you have given here:
First stomach pain: here if you have done all test but I just want to know how about
ultrasound of abdomen. If you have already done then what was the report. If report was normal then your pain could be related to
gastritis. And you need to take anta acid tablet daily one in morning with empty stomach. And along with this need to correct life style and food habits. Have break fast good, lunch average, and dinner minimum by 8:00pm or before that. Keep tea and coffee minimum, have more of mix cut fruits in your diet. As well do regular exercise like walking, cycling etc for 25-30 minutes.
If there is any specific issue reported in ultrasound abdomen then need to take specific treatment as per the diagnosis.
Now for back pain:
It can be related to
muscular weakness , spinal disc problem, spinal curve loss. How ever the conformation can be done with MRI scan of back.
Now here if report shows major damage then orthopedic doctor will suggest for surgical management. And if there is no major damage in report then it can be treated with
physiotherapy treatment, hot and
cold pack use, as well spinal exercises. This all in combination will help to reduce inflammation, relax
soft tissue, and helps to relieve pain.
Lethergy can be due to less food intake, vitamine b deficiency and less water intake too. So try to improve it and then check again.
In general I also suggest to do
yoga, and pranayama and live healthy life.
Take care.