why is my 04 silverado stuck in 4HI

What is your question?

I have an 04 silverado, and I am stuck in 4wd. I have the push button option and the light is telling me im in 2wd but I know without a doubt that im still in 4HI. Every now and then my lights will move from 2HI to auto 4 and back to 2Hi while driving down the road, but now none of my buttons will work. I have pushed the 4HI 4LO 2HI and Auto 4 buttons but no lighting nor engaging takes place, put it in nuetreal and reverse ect.. it still says im in 2wd. I cant switch out of 2wd on my push button, but Im still driving in 4HI. I also have what sounds like a ticking noise coming from under my truck which leads me to believe it may be my transfer case. Another problem is I sometimes hear a grinding noise in my front end when it says im in auto 4... any thoughts?