1998 Pontiac Grand Prix Car Quitting?

1998 Pontiac Grand Prix Automatic 200000 miles

I have a 1998 Pontiac Grand Prix and for a couple months now it I dont know how exactly to explain it, but like when your going up a hill {it doesn't have to be steep} my car will slow down to like 20 mph. When you stop it takes forever for the car to get up to 40 mph. Now, for the past couple of weeks it has had a very awful smell, someone told me it was carbon monoxide because sometimes it smells like gas and sometimes it smells like burning oil. Now when you go to crank my car it goes dead if you dont hold the gas down when you change gears, and the key sometimes gets lodged in the ignition. I know this is alot but I am in desperate need to find out what is wrong with my car. I am a single mom of 4 kids, and CANT be without a way of going. Layed off work for right now, so I came to this site instead of going to a mechanic shop. Well, if anyone has any information on what is wrong with my car and how I can fix it please e-mail me at chassity15@ymail. Com.
Thank you!