eat less often and eat more of the right things. you probably eat 90% hard to digest foods. to me it sounds like for sure you need to look into fasting protocols. it will help you tremendously with the stomach.
your body is constantly working to digest food, so you never give it a break. what is the longest you have gone without food? probably not very long. so you need to fast and give your digestive system a break. read my Ebook, it is in my signature, it teaches you how to do it