Oil smells like gas

[Rpbell]

Hey Ive been having issues with my 2003 Tahoe z71 edition fully loaded I took it muddin not long ago and got it buried it cut off with water all the way up the exhaust water wasn't touching the motor I changed the oil a couple times to get all the water out it was smoking real bad before I changed it afterwards the smoked stopped I changed my oil 3 more times within the same week and everytime the oil is blackish gray now it smells like gas and I have black oil looking stuff coming out of my exhaust I have to add oil every 2 days atleast because it gets low it's like the oil is thinning out and burning somewhere I just don't know what to do seeing that I have to drive this thing to work everyday atleast 50 miles I need help ASAP!