My theft light is flashing rapidly, somehow it.

My theft light is flashing rapidly, somehow it is in "anti theft mode"
I have tried everything from unplugging battery for 7 hours unlocking with keyless entry, unlocking with key, turning the key forward once until theft light stops more than 3 times before trying again. I have noticed while doing this it blinks rapidly for about a minute then stops for a few seconds blinks once stops again then blinks 6 times a bit faster. Repeats this 10 times. Then shuts off but car will still not start. :( Help! I didn't do anything to make this do this. The car was not broken into. Nor was anything touched. We filled gas to full. Then the next time trying to start it did this but start after a few times trying. Now it won't start at all