1997 Chevy Truck Truck turns over but won't start

I have never had a problem starting my truck until the past year. The initial issue was that it would have to turn over for about 5 seconds before it would start. I was told that it might be the fuel filter so I had it changed last year. It didn't seem to do much better. It has progressively gotten worse to the point that I would have to allow it to turn over for a while then pause and then try it again before it would start. I would then drive it somewhere and turn off the engine for a few minutes and try to start it back up and would start just fiine. Now it will just turn over forever and won't start. Would it be a problem with the fuel pump or should I try the fuel filter again? I also understand that 1997 was a bad year for ignition switches. Would it turn over like that if the ignition switch is bad? Please help.