The left side of my throat is sore and i have swollen lymph nodes. it's not mono and i have taken many tests and doctors don't know what's wrong?

See below: Could be an abcess tonsil or tonsilar crypt that is impacted---consider seeing an ENT for help.

Without knowing: What doctors have seen or the results of your specific tests it's hard to speculate. Irritation, trauma, pnd, viral illness, etc. At some point a biopsy of your lymph node may be appropriate. But, for now, i encourage you to make a list of everything you've discovered so far and review it to see if you need to ask further questions. Be bold! it's a good first step.

Sore throat: Most common cause is bacterial infection like strep throat or viral like mono. There are other rare causes , your doctor will work up for these if not getting better. If persisting and not getting better, lymph nose biopsy is an option.

PTA: Possibly a peritonsillar abscess? Hard to tell without seeing you. Keep following up with your doctors. They will figure it out.

Swollen gland: Likely what you are describing is something called lymphadenopathy, which is swelling and inflammation of lymph nodes. This can lead to pain and can be aggravated by movement, depending on the location of the swollen lymph node. Generally speaking, most lymphadenopathy is caused by infectious processes. This could be viral or bacterial. See an ear nose and throat doctor if not already.