Don't take meds unless you have a swab test come back positive for strep. You're describing the same symptoms my daughter had, and she was just diagnosed with mono. Her doctor prescribed antibiotics (twice!) and she had a horrible reaction. Turns out if you have mono and take antibiotics, you'll get a terrible rash and your skin will swell. (Not supposed to take meds with mono.) So now she's out the $$ for three doctor visits and two rounds of different antibiotics that are unusable.
Google mono and see if your white patches look like the pictures there.