First post, first TT, first of many stupid questions.

The sway issue is very important and needs to be addressed ASAP. But the struggling to accelerate and maintain speed may just be that you are not used to towing. It's pretty normal for a gas engine to really wind up the RPMs to get the work done. They were built for it. There are many drive line modifications one can do to improve towing performance, IF the suspension/sway issues have been figured out. I've comfortably towed similar weights with a lesser tow vehicle.