White Spots On Back Of Throat, Swelling, Pain. Fatigue, Fever. How To Prevent It? Taking Medication For Lupus

Question : For the past 20 yrs off and on I get white spots in the back of my throat, along with severe swelling and pain on either side of my throat. Sometimes the whole back of my throat almost closes and I am in severe pain. I feel fatigue, drained and have flu like symtoms also when this occurs and sometimes fever. The only thing that makes all of the symptoms go away is a steriod shot. Pain medication or the PAC do work. I do not know what causes this, or what I can do to prevent this. I have been diagnosed with skin Lupus, but all of my blood work says "no" to XXXXXXX lupus. My doctors do not want to continue with steriod shots, but no one can give me any answers to what "this" is for 20 yrs now at all. I have seen my regular Physicians and ENT's with no answer to what is causing this re-occuring severe issue in my throat. It is really painful and hard to manage when I have no answers. I really would like to know that this is, how to prevent it or what medication I really need. I have medication for my skin lupus and it works just fine. However, internally this has honestly gone on for too long without and answer or information on preventative care options.