1998 Jeep Cherokee

Within the last 2 years I have had a new water pump, a new fuel line, and a new radiator installed. Now.. no cold air blows out of my air conditioner, vehicle is leaking antifreeze, the 'coolant sensor bad' light comes on, and I can smell gas pretty strong inside my vehicle when I feel the tank up. I was told that I would need something else replaced to get the a/c to work, but I can't remember what it is. (heater core maybe??) Anyways... I wanted to know if all of these problems could be tied together and what could be causing them?
Thank you