Could be a STD?

So I had a hookup with a guy and I was dumb and gave him a BJ without any protection and then later that day I found out he has a wife. (No telling how many women he had cheated on her with) which he told me he was single. So I had no idea until I creeped on him. Anyways a month later I woke up with pain in my throat and I looked and saw this

Could this possibly be an STD? I also been having acid reflux at the time so could it be possible it’s from acid reflux instead?

Sometimes I have pain and I feel kinda throbbing but most the time it doesn’t hurt