1999 Chrysler Cirrus Cirrus leaked Gas and completely quit

1999 Chrysler Cirrus - I've owned since December 2001- I've had many many problems with the car. Yesterday at a stoplight, I went to accelerate, and it suddenly wouldn't go. The oil light came on and all dash lights came on. It has a faulty idle sensor so it cuts off here and there which is what I figured it was. But it would not crank up. I tried to crank it a few times, freaking out because I'm at a busy intersection, and a guy pulls up behind me and says there's gas all around the back of my car. So I get out and sure enough, there's gas spewed around my car.

The fire department had to come out and verify it was safe to be towed, and they looked under my Cirrus. They said it was obviously coming from the top of the fuel tank and asked me had I hit anything recently...I hadn't.

I had the Cirrus towed to my mechanic who I am sure is tired of seeing it. He did not sound positive on the phone when I told him what was going on with it. It has 175k on it, and has had every thing you can imagine go wrong except transmission failure. It's even had all oil valves replaced in 2005. In November, I paid almost $800 for a major tune up. My anxiety is so bad right now because I am sick of paying for all these repairs and knowing this car will be unreliable for me.

Can anyone make an assumption about what could possibly be wrong and about how much you think it will cost? Thanks guys :(