a lump at armpit

I have no solution for this. But i have a lump too under armpit since I gave birth to my firstborn 6 years ago. It’s quite big. It’s because I was so engorged post partum due to my baby being in NICU and I didnt know what to do. Im not sure if for your case, the lump may go down. U may try to breastfeed first and see how it goes. But for me, even after breastfeeding my second n thirdborn, the lump doesnt go away. I researched, it can only be removed by surgery. U may also want to ask your gynae or gp about this.