Car smelling strongly of gas, gets worse when parked. What do?

Obvious answer: go to mechanic. This is already part of the plan. The post is more for general assumptions on pricing and what it could be causing the problem.So, as topic says: my 2007, 125k mile Hyundai Sonata smells like gas baddddd. I'm currently on vacation freaking the fuck out as I'm supposed to leave tomorrow and I'm not sure if I'm going to be able to because when I'm parked it builds in the inside of the car and gets worse! This came pretty much out of no where adter making this 1000 mile trip.What I do know is I'm due (slightly past) for an oil change and am coming up on tire rotation. But how much do those things have to do with the problem? Again I'm sorry if this is an irregular post but again I'm freaking hard because I'm 1000 miles from home and my car smells like if I light a cigarette in it I'm going to explode.Help. via /r/cars http://ift.tt/2tZaJkQ