What the f

2 nights ago this HUGE random lump popped up on the outer part of my butt cheek, it has majorly gone down but now it’s a pea size lump or ‘ball’ under the skin that I can clearly move and also pinch together (kinda). It’s super tender to the touch!! Warm compresses make it feel better. Anyways my question is-how long until it’ll fully go away?