Avoid hard surface. Tk soft pillow or sheet. Hot fermentation. And consult with physiotherapist for exercise

First of all you need to change sitting habits with soft cushion above chairs, increase the hight of your chair at your knee level or little more ,not less.if still pain persists ,pls do hot & cold application of water(sitz bath)  ..20-30mnts 2times a day..if still pain persists pls go for physiotherapy modalities..thank you.

If it is tail bone pain- use doughnut pillows. If lower back pain physio then back muscle strengthening exercises will be helpful. Drink plenty of water to avoid dehydration because dehydrated disc is more prone to injury