Welcome!
Are you sure your Oxandrolone/anavar? If purchased from underground labs they are often substituted for other stuff. I would stop taking it until you can verify that what you are taking is the right stuff. Once you verify that you actually have Var and give yourself a couple weeks off you could try taking smaller dosages of maybe 5 mg and see if that reduces sides, but the most important thing is making sure you know you are on anavar.