Electrical/security reset, cranks will not start

My truck had been taking longer key holds to start indicating the usual need of a new gas pump soon. This went on for months, battery died while I was out, got a jump start and made it home. Had issues with truck turning over that led me to believe it was out of gas. No sound of the fuel pump priming. Fuel gauge was also pinned which I later read was due to a bad ground and fixed when I put in the new fuel pump and checked wiring and cleaned up connections. New fuel pump and new battery, truck still cranks but will not turn over. Have checked wiring from pump to tank. Have check grounds. Also bought new relay for pump. Now security light flashes, and truck cranks but will not turn over still. Still no noise of fuel pump priming. Have tried a couple of the security resets I found on YouTube posted by other Chevrolet 1500 owners, and have had no luck. Any ideas on what could possibly be the problem? I would very much appreciate any advice on the next steps I should take on solving this problem with my truck. Thank you very much.

Brittany