Idle drop/jump and raw fuel smell

00 v6 auto I have been having the code p0442 (small leak in evap system) go off lately. It seems to happen when Im at about 1/2 talk or less, then reset computer and refill tank, and it doesnt go on again untill about 1/2 tank or less... I just got a new gas cap, hoping to solve the computer problem. Well I havnt gotten down to 1/2 tank or less yet since the new cap so im not sure if ive solved the problem. I have noticed today at a stop sign my idle fell to about 400rpm then went up to 1000rpm then slowly went back down to 700rpm, its normal idle. After that episode it just ran like normal, untill i got home into my driveway and as i put it in park... maybe 30 seconds of just messing with crap in my car before i shut it off it did the same thing agian. I also noticed when i got out of the car, a raw fuel smell.... I popped the hood and sniffed around but i think it evaporated. ANY ideas?

Ive read around about cleaning my IAC or replacing my TPS but honestly do my seperate problems sound like they could be linked? maybe a vaccuum leak? Im not sure -- To be honest, Im a carburated Jeep girl, and cars with computers scare me