21 years ago I was diagnosed with an abcess behind my right tonsil. It was more painful than any tonsillitis or strep throat I had ever suffered in the past. My jaw would only open a fraction and I was only able to use a baby spoon to force a few bites of baby food down my horribly pained throat. I could barely talk. My voice sounded strange. The common term for it is "hot potato voice".
They removed the tonsils and lanced the abscess. I was hospitalized for four days due to dehydration. (I would not eat or drink unless forced because it pain was so intense)
The pain from the tonsillectomy was far easier to handle than that of the abscess.
Anyways, in the years since that operation, I have had one possible recurrence about ten years later, which burst while I was actually at the doctors office waiting to have him tell me what it was. I was never told anything since it burst before he had a chance to look at it. The relief was immediate, after unfortunately having to allow my stomach to void itself of the vile contents of the abscess or cyst.
I mention cyst because I have just come from the doctors office seeking help with a lump in the same area as the last one. It hurts, although not at badly as the first two, and is the size of a tonsil. It is causing my right ear canal to be tender as well. My doctor said it is a mucous seal/cyst which requires no antibiotics. he suggested that I gargle with warm salt water a few times a day to try and cause the cyst to burst. He referred me to an ENT doctor is the cyst hasnt ruptured within 7-10 days.
I dont know if any of this has helped with your question, but I thought it might help to either rule out abscess and cyst, or maybe help with a better understanding of what you are dealing with.