Lower back, hipbone injury

about 2.5 mos ago,itook a fall on stairs and landed full force on my lower bak,top of bone next to base of my spine.had a massive bruise for about 2 mos.bruise healed but still have constant pain and pressure at site.also noticed cold sensation in lower bowels and bladder.also have a mild burning sensation when urinating.i am also having waves of nausua i'm sure did not start until i injured myself.