Towing and transmission issue

[RGSMDNR]

I guess im just disappointed in the lack of power this truck has while towing. I wasnt sure if it had anything to do with the tranny temps or not. I dont pull all that often, but when i do its just frustrating trying to maintain highway speeds without having to step on it every so often to get it back up to speed. Would the hotter tranny temp be robbing that much power??