Having some trouble with bm

I have been having some trouble with bm latly. It has been going on for about two months. Nothing has changed to cause this. When I go to the bathroom, it is really soft, wet and sticky. Afterwords I can't get clean. I wipe for ever, using about a half a roll of toilet paper, and then i still have to get in the shower. THis happens every time i go to the bathroom. It makes me burn and itch down there all the time. What should I do to help with this?