You may have an anal fissure or a small tear in the tissue of the anal sphincter (there's actually two in close proximity - it's the inner one that's involuntary and needs to be relaxed for anal sex to be comfortable). You should rest and recover, or you risk further damage.
Long term damage, especially from "hard poundings", is not something you want - there's the risk of chronic haemorrhoids, rectal prolapse and if you rip/puncture the rectal wall, you're going to be in a very bad place.
Never use "anal-eez" or any numbing ointment - the pain is there to tell you damage is being done and you need to change technique.
