Because you have a crew cab, and a long bed, the weight of a camper will fall on the rear axle almost completely. The best suggestion might be to fill your truck with fuel and what things you might carry, then weigh the axles. Look at your tires and see what their capacity is at maximum.
That difference then becomes your ability to carry a camper loaded with a years supply of everything you need. You may need 19.5 wheels and tires to make it work for you if your axle is rated high enough for the load.
Remember, the posted dry weight of a camper does not include jacks or A/C either, and generally without any options, so weight really adds up.
Good luck.