Suggest Treatment For Pain In The Throat

My husband is 31 yrs old and has been dealing with his tonsils become large and inflamed since March. The first part of March he complained of his throat hurting fatguie pain all over and high fever. This lasted for 4 weeks and he was given a Z-Pak, steroids, Clindaymycin 300mg and finally Amoc-Clauv 875mg. We say at least 4 different doctors and we had all the test done; mono, strep,cbc's all came back negative with no sign of what was causing him to feel this way. Then 4 days ago the symptoms have come back and with the same force as before. We went to a clinic but the NP just looked at his throat said infections and gave another antibiotic. I cant afford to have him miss a whole other month of work due to this breaking him down so, is there anything to do besides continually trying different antibiotics.