trans problem

I Have 99psd with a automatic and yesterday pulling my boat I got on it pretty good from a stop, and found it would not shift past 2nd gear and would not shift up all the way home. 1st and 2nd seem fine they up and down shift good coming to a stop and taking off. It just wont shift past 2nd. From park to drive or to reverse seems it takes longer to respond. Is my tranny done for or could this be electrical or something.

Any help would be great.
Thanks ahead, Ryan