My stomach is gettin hard in the middle and I been getting lower back pain and preusser and head aches I don't know what's goin on?

YOU NEED TO SEE. A physician and get diagnosed please.
See a doctor. You should really see a doctor to get checked out. I cannot diagnose without face to face visit. If you do not have a doctor you should see if there is a medical clinic in your area. Don't ignore these symptoms. See a doctor asap.