I get it and I'm sorry that you're feeling the loss of a significant relationship but you don't enjoy that lifestyle and that's okay. It's not okay to ask him to change for you this young and you shouldn't change for him either. Hope you get a physician who can help you. Stress is a huge cause of gastric problems and if you can address that it may help with it. Also couldn't hurt to take a medical grade probiotic like alforex and see if that helps too. Another thing is keeping a food and health diary so you can see if any particular foods are causing it. Hope you feel better soon

He's doing what a lot of 22 year olds do, you aren't interested in that lifestyle and both positions are fine. He's asked you to go out but you didn't enjoy it and again that's fine. But there's an incompatibility between you two that isn't going to be worked out because you view your lifestyles so differently at this point in your life. Hope you things work out for you both in the future