Car cranks but doesnt start

I have a 98 Tahoe.2 dr. 4x4.140,000 miles.
like 2 weeks ago I notices that I would hesitate to turn my truck on.I would have to crank it like 3 times b 4 it turned on. With time I would have to crank it like 4 times then 5 times. And now it cranks but wont turn on. Since then I have changed the fuel filter, spark plugs, whole distributor, and still no luck. Like a week ago I would turn it on but I would have to add starting fluid to help it start. When the truck would start with the starting fluid hlp I t would start pretty good but then I would step on the gas peddle and it seemed like the truck wanted to trun off and it would shake for a couple secs. I know the truck passes gas from the bak to the front because I checked that valve (looks similar to a inner tubel valve of a bike) and I pressed on it and gas squirted out.I know I have spark. I checked the spark from the distributor and the spart from one of the spark plugs. The motor also next to the gas pump is working too.
Right now my truck cranks but it doesnt turn on at all now. It wont teven turn on with the starting fluid help. What I do know is that one of my catalytic converters is bad. It rattles and sounds like rocks are inside of if when I stop in a stop sign or something. Might this catalytic converter be the reason my truck doensnt turn on? I noticed that the catalytic converter was bad like a yr ago but I never paid attention. Hey, even though the gas passes from the back to the front, might the fuel pump still be bad and have to re replace?