key is stuck in the acc position?

The reason your key won't turn off is because your shifter button is stuck if the shifter doesn't fully release in the park position then the little micro switch on the shifter assembly doesn't allow the key to be turned off. So does the shifter lock into park?Meaning you don't have to push the button to pull the shifter out of park? Your going to have to get into the shifter to see why it's sticking.

the shifter itself can move to all positions so i think it is the sensor and the button just stays inside the knob so its gotta be that piece inside that makes the button go in and out because it seems like the spring or whatever it is is shot

It's the handle or shifter assembly sticking i have even seen the lower part of the shifters get bent and not allow the buttons to release.If you fix the shifter not sticking you probably will fix the problem with the key not turning off.Do you need instruction's on how to pull the center console so you can see why it's sticking?

the shifter is not sticking tho it moves fine its just the button on the shifter is broken

If the shifter moves without pushing the button the button is causing the shifter to stick in the release position and also causing the micro switch on the base of the shifter to not allow the key to turn off.Have you removed the shifter handle to see if that is what is causing the shifter to not lock into place?