Why is my tummy rock hard still 2yrs after giving birth i workout i still look pg i'm not pg my tubes r tied & my period is irregular what could it b?

Tough to say: It could be due to weight gain from pregnancy. I usually hear about soft, fuller stomachs after pregnancy. Visiting with a plastic surgeon would help educate you on the cause.

Acidity?: I also do not know what you mean by acidity. As a young person, if you are having abdominal problems from gallstones, the best would be to get a referral to a general surgeon to review & see if laparoscopic cholecystectomy would benefit you.