Talk to Gastroenterologist on Gastroentestinal

assalam o alikum sir age 22 weight 47 symptoms from past 1 year problems:- 1 loss of appetite 2 fatty stomach and belly without eating anything but the body is soo weak 3 feels like stomach is empty but cannot able to eat anything 4 always low on energy 5 cant able to eat sweets dishes when i eat something sweat feels pain in the head 6 cant concentrate on things forgot things in seconds low on memory 7 cant feel thirsty even in ramzan drink only 1 glass of water in aftari sir please tell me which tests should be done before visiting any doctor and kindly suggest me best doctor according to these symptoms i am tired of life i want to live a life a healthy life . thanks in advance