Transmission or something simpler?

Given the symptoms that you have described and the possible cause list for this code, I'm gonna say it's a deteriorated transmission. How many miles does this car have on it? Have you ever had a trans flush? You could try to drop the transmission pan and see if there are a bunch of metal flakes in the pan which would mean the trans is coming apart. Or you could take it to a trans shop and have them check because some of the other possible causes are internal and would have to be chacked by a shop anyway. Good Luck. Please write back and update. Thanks.