I use to get a cyst (pimple like) thing between my buttocks. it is outside anus only. i feel paining while sitting sometimes and even once it got popped accidentally and a small amount of blood had come in my bedsheet. what shall i do to get rid?

Abscess treatment: The definitive cure for these is often simple surgical opening & removal of contents. Left alone they often spontaneously vent/drain only to re-accumulate germs & pus because a capsule/rhine is left behind that does so. Sometimes a small one will self heal if you apply heat to the area which improves circulation & allows better access to your own healing factors.