Doubt it is std related. Rather, this is the time of year in which sore throats happen. We turn on our furnace, weather is funky, etc. It's possible to have one virus and then another right after. If it continues, see an Ear Nose and Throat Doctor. Do you have allergies? Could you have mono (are you fatigued as well?)? I think you need another follow up. good luck
you might want to see an ENT specialist in case it might be thyroid related. I would also recommend echinacea, have you heard of this herb?
Hello~Sounds like a minor infection to me, has the doctor done a CBC to see what the white blood count is? Also, have you been tested for mono, this can cause the sore throat as well.