I Have Been Taking Candesartan (16 Mg) For Headaches. I

I have been taking Candesartan (16 mg) for headaches. I have been taking this medication since November 25th. Friday I started experiencing flu like symptoms; fever, aches, achy lower back. Saturday I started getting ulcers in my mouth. They are big and painful. It started off with two and now it is up to five. Also the gums around my front lower teeth are sore and have turned white at the gum line. Is it possible these could be side effects from the drug