My 4wd light is blinking in my 2003 Chevy silverado

I would not say "panic" - but I would say your 4 wheel drive system is not going to work until you resolve the problem that is causing the light to flash. If you are needing 4 wheel drive, it will not work until this is resolved. Testing will be needed to find out what has malfunctioned. It could be related to the electronic transfer case functionality, which will shift from 2 to 4 wheel drive and back when selected.