Being an ex mech, it could be a list of problems from trans to mass air flow sensor to clogged up cat converter to bad gas ... get a good mech to check it out.
I have a 2005 trailblazer, when I go to accelerate it's like I have no power even floored I can't go over 20 30 mph?
I had that problem with a VW Beetle, going uphill ... 2 of the pistons were shredded
your catalytic converter might be clogged, or could be a transmission problem.