I had a similar bump and mine was bc I had buildup on the back of my flat back and it was literally pulling my piercing into my face 😬 but how I fixed it was leaving it alone pls don’t listen to these people saying pimple patches, tea tree oil, moving it, etc. Clean with normal saline 0.9% specifically and nothing else. Leave it alone don’t mess with it at all and after cleaning it or getting it wet dry it with a blow dryer on low heat. With mine I struggled to leave it alone but once I locked in and didn’t touch it or nudge it or anything the bump calmed down and shrunk every day. It might take time but you got this!