Feel dull and tense. Same as before.

Hi. I am 25 years old. From last 3 years I am facing particular problem. First it was digestion, couldnt clean stomach. Now it is okay upto limit but other problems are still affecting life miserably. Like feel always super dull, unenergetic. Like my body is rotting in inside. Whenever i wake up there is bitterness in throat. Also couldnt slerp properly. It is affecting my performance in studies and especially social life. Please help me. I just want to feel refreshed like it was earlier. Consulted gastroenterologist once. He checked and told there is nothing wrong. And gave one powder and sleeping pills. After that digestion improved a bit. But the dullness and that rotten feeling is persisting (pimples come regularly). But whenever i exercise all is good for sometime but after 2-3hours all become same as before.