Loss of gauge cluster and Transmission seems stuck in second gear?

The other day I came to a stop and the truck shut off. It started right back up but when I pulled it out it seemed a little sluggish until the RPMs got up. Well then, I noticed that I lost all my gauges except for the oil pressure and battery. No prnd21 or miles lite up on the display neither. It also used to blink service 4x4 but that no longer blinks when it's running now. Also, the engine light is on which it was before. Code for the knock sensor. So, I realize I lost my gauges and I am on way home every stop I feathered the gas so it wouldn't stall and stopped short each time in hurry up and pulled out. I eventually noticed that it seemed like it was in second or third gear because it would start to tac out around what I'd say was like 50 MPH. When I got home and messed with it, it will blink security on the left side where the digital display is but as I said no longer says anything with key turned or on. I tried to read some things and come up with possibly and ignition switch. Well, I got one from the junk yard but needless to say with no luck. It didn't change anything. And as I was taking the old one out and moving wires around, I tried to see if anything would start to work if there was a loose connection but no luck. I also read it was an instrument cluster. I got three from the junk yard although they are the ones with the two lights on the left bottom corner for whatever that's for. Mine had the Transmission temperature there because it's the HD I guess. So, not sure if that matters or not but I did try changing the gauges and no luck either. With the old switch and with the new. Because the switch I got from junk yard was a 10 pin like what I needed but came from a normal 01 1500 that had the other style dash than what I had. At first I thought that was the difference in the number of pins on the connector but then seen that one had only 10 like mine but that's irrelevant. If anyone has any ideas of what I can try or how to diagnose the problem I'd greatly appreciate it. I'm at a loss. I can add videos and pictures if it helps. Let me know.