As you mentioned that you are a body builder , so also doing hard exercises . The cause of concern is loss of weight , so be careful about your diet . These measures may be useful for your bloating and abdominal distension i.e. indigestion. Try raising the head of your bed about 4 inches with blocks. It might also help to avoid eating or drinking for 2 hours before you lie down. To help control stomach bloating or distension one should over drink or drinks with caffeine in them or eat chocolates or spicy or greasy foods. Also take some antacid but if bloating is severe , you may need drugs like proton pump inhibitors like pantoprazole . Some enzymatic preparation may be useful for you. If weight loss is continue then consult a physician and get complete examination. Good luck.