I am 48 yrs old. u/s diagnosed with adenomyosis with no bleeding, bilayer thickness of endometrium is 5-6 mm get lots of pain. what else could it be?

Adenomyosis: Ultrasound can't make the diagnosis of endometriosis, it just suggests it. It could be endometriosis as well, which may give you a completely normal US. It could also be worsening dysmenorrhea (period pain) and lastly you still have to consider pain from other structures like the bladder, bowel and nerve pain of the abdominal wall.