2002 Chevy S-10 Engine wont pull good

I just started having problems with my new/used truck, I took it to autozone and had the codes checked. It was my crankshaft sensor. I bought the part but couldnt find out where it went so I kept driving it until it got to the point it wouldnt pull uphill at all, and started dieing. I replaced the sensor today and now it was able to pull slowly up a hill, but it wouldnt go faster than about 10mph at best even on flat ground, uphill was much slower. The vehicle ran great before the crankshaft sensor started going out and now when it sats idling I can rev it up in park to about 2000 rpm and then rev it up again to 1900 or so and every time I rev it up its lower and lower rpms until it goes bottom at around idle which is 1000 rpms. Any ideas