Doing masturbation frm 8 yrs now m 22.i feel abdominal pain and back pain mch.my belly is also going so big i am worried alot.is it due to mastrbation?

Abdominal pain: Highly unlikely,unless you are inserting a finger in your anal area and then around the vaginal area which technically could cause a UTI. Otherwise do not worry about masturbation. Regarding your abdominal pain would check with urgent care/ doctor within 24 hours maybe urinary tract infection, gastritis,gastroeneteritis, food intolerance,gallbladder, pancreas ( if drink alcohol) or pregnancy

No: It's not due to enjoying your body, but if your abdomen is increasing in size, your physician needs to evaluate you.