Engine not starting

Almost four weeks ago, my Saturn decided it did not want to start, and I have no idea what to do at this point.

1998 Saturn SL2, 184,000 miles on motor, approx. 105k miles on transmission.
Things I've had replaced in the past 3 years: Coolant Temperature Sensor, serpentine belt, water pump, serpentine belt tensioner, valve cover gaskets. No aftermarket or performance mods. As factory as it gets.

On the day it quit working I drove it to work, just like any other day. One thing I noticed upon the cold start was that the RPM's weren't going that high up (went to 1500, then immediately to 900 or so). I thought nothing of it as this car sometimes has a mind of its own. I made it to work just fine with no other problems. Then when I go to leave, the car starts up fine, then immediately turns off. It cranked but wouldn't start. I waited about a minute, and it started right up. Then I drove down the way a bit, at low speeds and it tried to die out at a stop sign but kept going.

So I get to my second job just fine, but when I try to start it and drive home, it would not start. It cranks like normal, but nothing seemed to catch. Because it was raining heavily, I decided to check what I could and noticed the air filter was damp. I replaced it. Also, as a precaution I replaced the spark plug wires. After sitting over night, it started right up and I let it run for a bit. Then about 7 or 8 hours later I went to start it up, and no start again (that was the last time it ran). A friend tested the wires and sure enough, no spark.

Next, I removed the coil packs and control module - they were soaked pretty bad. I cleaned off the connectors and grounds and bolts. Let them dry for a few hours with a fan on them. Put them back on, and nothing. I went ahead and changed the Ignition Control Module, still no start. I changed the coil packs, and still, no start. I had the car towed to my house, and was told also I should change the crankshaft position sensor. I also have changed that out, and no luck.

My battery is about 4 months old, but it ran low so I slow charged it over night. I'm not sure if I'm getting spark or not, although before I changed out these things, I could see the tack and speed gauges jump when starting, but then they quit doing that. Sometimes they jump, sometimes, they don't.

At this point, I may have to take it to a shop, but I'm strapped for cash at the moment and I can't afford 500 dollars for someone to tell me that my fuel filter is bad (it probably is).

Here are some things I noticed in the week leading up to the no-start condition:
The car ran a little rough at lower RPMs and lower speeds. It also seemed at points like I lost some horsepower, but then it would work itself out. The transmission shift points were higher than normal (right after cold starts only). Engine light was on - OBD II said it was a front oxygen sensor. (Important to note that light only used to come on when it rained?). MPG went down a little, but no more than 2 or 3 mpgs.

Other than that, everything was running just fine, until it quit starting.

Again, it cranks fine, fuel pump primes as normal, and everything electrical works. Windows, lights, radio horn, etc. But it will not start. Also, my starter sounds like it's beginning to labor a bit, so I'll have to replace that soon after all of this.

Also, I do not have any volt meters or any way to test this thing out here. I can borrow some this week. Where would be the first place to start looking?

Thank you for any help or suggestions.