Hi welcome to Health care magic forum.
Thanks for calling H.C.M.F.
Your taking oxylite pro has nothing to do with the present weakness. Since november you gained 15 lbs, and getting stomach pain in the lower abdomen.
The lower abdomen pain suggests urinary tract infection
, stones in the urinary tract
, worms in the intestines, if on the right side may be chronic appendicitis
, or tuberculosis
of iliocaecal junction, if female it may be pelvic inflammatory disease
, or endomatriosis, or P.C.O.S.
I advise you to consult a surgeon for diagnosis and treatment. You may need to have M.R.I. besides Other routine tests for confirmation .
Wishing for a quick and complete recovery and thanks for calling.