@tinatoren
If you have been abusing your neck, check out Occipital Neuralgia.
There are easy neck stretches that you can do that will help alleviate the pain in your face etc. You can see videos on YouTube.
I am doing the stretches myself to keep my head from hurting.

The stomach issue is a common problem from my experience. I had to finally get a prescription acid blocker myself. I take Pantoprezole because the aspirin I take for my heart tears my stomach up. The same with Prednisone. My stomach hurts with those things.
Blessings
Susan