Take some Codine. Or Co Dydramol

Give it a little bit, relax and apply heating pad/warm damp wash cloth to see if it's a muscle.

If you move around and it gets worse (a lot worse), doctor ASAP

Is it above at or below waistline?

it's RIGHT on my tail bone i've taken a bunch of hot baths and stuff but none of that seems to help

Keep weight off it, sounds like some sort of stress on it. See if it gets less painful with time or overnight

If you spend a lot of time sitting, it could be a compression injury. Is there any constant, burning pain associated with it?

no not really

Okay. That kinda rules out a bulged disc that would put pressure on the surrounding muscle and cause a burning sensation and sharp pain while straightening after bending. For pain while sitting, I would look into tailbone compression. Does it get better when you stand?

yepperonie, right away

It really sounds like compression. Or at least something being exacerbated by the compression. When did it start?

Could be a cyst maybe?

That happens when you sit for prolonged time with the wrong posture.
May I suggest you to get up every hour of sitting and stretch a little?
Also, try to keep your back straight when sitting.
Actually, since a common suggestion is also to take a small sip of water every once and then (for other health reasons), maybe you could work with an hourglass. After an hour or two, when the sand is empty, get up and take a sip of water from the kitchen.
Then back to work.

^ This.

Happens to me all the time

Well, today i read a work about the fact that staying still for too much time was bad for human health.
It also reported that walking for 3 minutes every 30 of sitting is enough to eliminate every symptom induced by this bad habit.

Oooh, thanks for sharing your findings! o3o

For sure my buns want me to get up that often! It's interesting to consider prolonged sitting a bad habit, but it makes sense.

I'd suggest actually seeing a doctor or something about it. Better to be safe then sorry. D=

I got that and went to the doctor. They gave me a screening and I got scoliosis apparently. Now I'm gonna get physical therapy for it. So, I say go get it checked out. You never know what it could be.

"Doctor it hurts when I sit" "Then don't sit" Biggest suggestion is to not sit on your butt for a while, exchange between working while standing, on your knees, and laying down, preferably on your stomach, but side will work. Take anti-infamitories to reduce any swelling in the area. Reducing the swelling (even if it is unseen) will speed up recovery. 2 Aleive a day should reduce swelling quiet nicely (along with the pain). Do this for a week or so. That's my biggest suggestion. That or go to the ER and have the docs give you the same advice xD (and a much bigger bill). Definitely keep off it though if anything.

i'm a physical therapist... Message me if you want my advise/help. I'd have more questions for you and whatnot.