2005 CTS 3.6 Transmission Issue
 

Just last night my transmission started revving high without output. Today I started it and it began driving normal for less than a minute then began revving high again without output but still moving a little. I turned the car off, and turned it back on and it began running normal again for a moment and then stopped moving all together very shortly after and was stuck in the street, all while stepping on the throttle with no output. I let the car sit for a few minutes and tried again and it began to drive enought for me to get to my garage. It stopped again, I let it sit again and drove it to get it into my parking spot. I assuming it's the transmission. I'm hoping it's something small that you guys may know of.