Talk to Gastroenterologist on Weak Appetite, Low Weight

السلام علیکم I'm having digestion problems lately.. Even if my stomach is empty, I don't feel hungry. And after eating something, I constantly have burps for hours, and don't feel like eating much, when eating. Weight is lower than my normal, even after a balanced diet. Aur jab raat ko sone kelye laito, to mathe ke dono sides me dard sa mehsoos ho rha hota, aur left portion of brain relax sa kar rha hota he, jese pora din dard me ho,ya sun hoa ho...