Check Engine Light - Transmission

What is your question?

So my Durango's check engine light went on and my transmission seems a little problematic. I was driving the other day and my I felt a big crank as if the transmission shot into another gear. Then when I came to a stop and started again it was real slow to get going, as if I was in like 2nd or 3rd gear. Anyone have any similar issues or know what this might be?