Zach Powders

I have a 2011 ram 3500 dually cab and chassis 452,675 miles , blew an injector so I replaced all 6 , ran good for about a week , after said week I started experiencing no power at all , can barely drive up hills , can cruise 85 but as soon as I come to a slope I drop 20mph. Codes read low fuel rail pressure , cyclinder misfire 1-6 and N0x sensors.. many are saying my dpf is clogged causing the engine to reduce fuel to keep from blowing it up.. I want to delete it but I don’t want to put anymore than I already have into if it’s pointless.. I bought the truck with 400k on it to use at work.
anyone have any idea what the hell could be happening , I also have a loud shriek when my engine break is on it only happens sometimes