My 2015 silverado with now 90,000 miles on it started fluctuating on the RPM gauge on my way to work. i kind of felt a little jerking to it going up hills. i continued to drive it, as i was already 2 1/2 hours from home and still had 2 1/2 to go to where im currently working, by the time i noticed the jerking and fluctuation. when i finally come to a complete stop in a drive thru to get something to eat the vehicle would not move forward any longer, but would struggle in reverse.
any advice on where to start looking for an issue would be greatly appreciated. thank you.