Jerking so much I can't drive car.

I was on this site a couple days before Halloween because my 96 Neon had been shutting down, always just a few miles from home. It always cranked right back up, but a week before Halloween, it didn't. I was on here asking about the starter. I ended up putting in a new starter, and the car cranked and started beautifully. A few days later, it started shutting down again, same as before, except now it was every time I drove it (always 6 miles away from home, and it would be perfectly fine the rest of the day). I was getting a code 11 and something else to do with the cam sensor, but I can't remember the other code now. I knew the cam sensor looked pretty sad, so I replaced the cam sensor a couple of weeks after putting in the starter. As soon as I put in the cam sensor, and went to crank the car, it would crank but not start. So I checked things with the multi-meter and determined the problem was the crank sensor. So I replaced the crank sensor. By this time I knew there was an oil leak somewhere. At any rate, once I replaced the crank sensor, the car started. A few days later, it started jerking sometimes when I drove it. It was at any speed and after driving it for a while, and it was getting progressively worse after just a few days. So I checked the code again and received a 43, cylinders misfiring. I just put in new spark plugs in April, but I checked anyway. There was oil down in the spark plug wells. So I bought new spark plugs (again) and a valve cover gasket (plus seals/ grommets), which is where the leak was coming from. That was yesterday morning (Saturday). So I test crank, and it starts fine. Then this evening I went to test drive the car, and it was jerking so violently that I only got about a mile and had to turn around. Now, I'm back to seeing a code 11, which is about the timing belt, cam sensor, and crank sensor. It was dark already, but I went ahead and checked the cam sensor, which is fine. I looked as best I could at the timing belt, and there are a few small cracks on it, but how do I know if that is the cause of this problem. Also, with all of this happening one thing after another, is there a chance this could be some sort of computer problem, or that the car is just done? I don't want to keep dumping money into the car (that I can't really afford) if she's just headed to the big garage in the sky. Is there something I'm missing, something else the problem could be? I'm pretty lost with what to do with it at this point. Please help if you can! Thanks!