Question
On thursday me and a friend were doing deadlifts( we were doin max reps i had a little trouble out of the 5 attpemts i did 3) and i know on one of the sets i had TERRIBLE form. now my lowerback is killing me around my tailbone kinda its about it around the spine. i dont know if its cause im sore or an injury. this was 5 days ago now i still have the pain and the sort of pain that is sharp. like when i move i can feel the sharp pain from that area. i dont know what it is sorness or an injury. it its an injury what could be wrong?

UPDATE: its been a week now and the pain is still the same if not alittle better. i got my mom to stretch me out and massage me a little and it got a little better. im really scared because idk whats wrong with me. when i was deadlifting i didnt hear a noise or anything just the next day i woke up and i had pain. when i move my head down i can feel the pain. its on my lowerback above the tailbone.

Answer
Most likely, you caused a sprain/strain to the ligaments and muscles of the lumbar spine.  I would suggest that you see a chiropractor for an evaluation.  They can best choose a course of treatment and rehabilitation, and, if necessary, send you to the proper specialist if need be.