Frequent weakness. Weakness still same.

I have been suffering from stomach issues since 2 months. Medicine temporarily give relief but its recurring. Though the severity level has reduced drastically. Now I feel stomach warmness before meals mostly. But last 15 days I have general weakness frequently. All my blood reports and sonography reports are normal. CBC, sugar, thyroid, vitamin b12 (300 pg/ml)  vitamin d, ferritin, kidney, liver, lipid. Also abdomen and pelvis reports normal. As per my observation whenever I take Pan d I feel good for 3-4 days and again weakness hits. Also, whenever I pass stool specially in evening time i feel totally drained with no energy. No other symptoms. I pass stool without any drain and no issues with bowel movement. Please help me understand what could be reason for frequent weakness. Also taking multivitamin syrup for weakness still same.