Miserable for 5 days HFM? Symptoms started after covid shot?

I got my first Pfizer COVID shot Friday 9/17. An hour later I began to have the joint aches and pains and my face felt flush but no fever. i thought that was normal and it got better the next 2 days. Then Monday the 20th the aches and pains came back with a cough. Got tested for Covid, strep, and flu. All negative doc said just look out for fever. I ended up spiking a fever tuesday night so i called doc back and they said come back and get re tested Wednesday. again, all negative. She prescribed an antibiotic and allergy meds but never said what was wrong. I continued to have fevers and cough thursday. Friday (last night) I noticed my mouth hurting and realized i had little red blisters on my tongue and blisters around other areas of my mouth and throat.

I took care of 2 babies at the daycare i work at that ended up with HFM. I have been miserable just about all week. feels like my tongue is swollen. last night i woke up in pain, felt like blisters were wrapped around my teeth or something. Also i have been coughing up brown gunk. My head hurt today and neck has hurt. Is this HFM???