antitheft wount let me do nothing and cant get it to reset
on 2004 Chevrolet Silverado 1500

wount even let the ob2 scan

I gather it won't start, correct.
Do you have AAA plus for towing? If not it only costs $99 for one year for four tows over 100 miles. Best money you will ever spend.
If not tow it to a PROFESSIONAL AUTO TECHNICIAN to diagnose the problem properly. You will not be able to scan the antitheft side of the PCM with just a OBDII code reader. If you don't you will spend a lot of money guessing.