Could Mucus In Throat Be The Cause For Difficulty In Swallowing?

i went to the hospital with a high fever adnbody aches and soar throat on monday and they said i had influenza. i was give a couple bags of fluid and sent home. since then i had a couple days of body pain and tiredness. then as i was started to feel better i began to have cold like symptoms. 2 days ago my voice became slightly hoarse and this morning i can barely speak. as well it hurts to swallow. i checked the back of my throat and noticed i had what seemed to be trapped mucus around my tonsil on the one side. what could this be? is this causing issues with swallowing and my voice to go?