Hope you have completely recovered from the seasonal influenza
The swelling in the right armpit could be furunculosis
(infection and inflammation of the hair follicle), caused maybe by scratching or excessive sweating
Advice to cleanse the armpit with Warm water , air dry and then sprinkle or spray Neosporin
Do not use any rough cloth or sharp articles.
If the pain / swelling increases - consult a Gen. Physician / Gen. Surgeon for evaluation and right course of antibiotic.
Wish you quick recovery.