Could My Swollen Tonsil, Sore Throat, And Unexplained Muscle Pain Be Something Serious Or Contagious?

hello! i have a bit of pain in my muscles from them being very sore (i havent worked out or done extracurricular activity lately) and one of my tonsils its very swollen and inflamed and it hurts to swallow and also just exist as a whole. i am so scared i am dying or that i might get my friends sick