what's wrong with my tongue?

okay, so I’ve had my tongue pierced for like 4 years now and I’ve never had any problems with it. it’s never been infected or anything. but the other day I noticed that my tongue was sore, I figured I must have just been playing with my tongue ring too much and it got sore. but then it started to hurt worse especially when I eat or chew. it almost felt like I had bitten my tongue bad or burned it. so I reached in to feel my tongue and discovered a marble sized…okay maybe pea size or blueberry size…lump IN my tongue. not ON it, IN it. it’s not around the piercing hole but it’s in front of it, right in the middle of my tongue. I thought maybe infection but it looks fine and it’s not the piercing that hurts it the huge lump. you don’t notice it by looking at it, only feeling it…well maybe the lump area it a bit red and swollen. I have no idea what it is! I’ve tried mouthwash just incase it is an infection but it doesn’t seem to help. any ideas?