The DU Lounge

(It's that little projection of the spine below the pelvis that used to serve the purpose of supporting a tail, even for those of us who don't have one. Now, it's an anchor point for various muscles in the back, hips, and possibly legs. I turned to the side too quickly while I was bending over and my body's own momentum exerted the stress that pulled the ligament.)

I told the doctor I was worried I might have gotten a hairline fracture. She shook her head sadly and informed my she had once fractured her coccyx and said it hurt a Hell of a lot more than what I was going through. Prescribed cure was HUGE doses of acetominophen (Tylenol); at low dosages, it's an analgesic, at higher doses it's a powerful anti-inflammatory. My Rx called for six 1000mg tablets (Rx only) four times a day. Not something to try without doctor's recommendation, but you might try checking your OTC Tylenol for the maximum daily dose, and giving that a shot, if it's consistent with your other conditions/Rx's.

If you already have a donut cushion, see if it helps.

There's actually a medical condition known as https://en.wikipedia.org/wiki/Coccydynia -- lots of info at the Wiki (amazing how much there is to know about a part of our anatomy we're usually scarcely aware exists). Hopefully you won't have to have a https://en.wikipedia.org/wiki/Coccygectomy.