My truck is bogging out really bad when shifting and downshifting in higher gear

What is your question?

So my truck doesn't seem to want to push past 3000 RPM. It refuses to downshift properly without me punching the gas really hard. This happens mostly in the higher gears, like when I get around 50mph and up. If I am coasting and go to push on the gas, the front end just shakes n bogs out really bad and wont catch. I've had everything inspected by a mechanic and they cant seem to find the problem. Changed the oxygen sensors, and did a fuel injection cleaning service, but that did nothing. He told me to run it with the over drive off, and it runs a bit better this way, but still doesn't want to push past 3000 rpm. Is my trans shot? Thanks for the help in advance.