Losing power is a lot of times due to a clogged catalytic converter, have that checked out.
loss of power under a oad is a good indication of a clogged catalytic converter
I would say it's a slipping clutch
Yes, if it just started in time you will lose power and speed, replace it, it is breaking up inside.
maybe you need a new alternator
The transmission doesn't lose power, but it quits getting power if the clutch starts slipping. Without going into detail about the physics of a clutch, the most energy is being transferred through the clutch when in the highest gear thus it is fifth gear where slipping is first noticed. My guess is its time for a new clutch.
Yes, if you had to make a sudden move at highway speeds you may lose control.
Sounds like you belt came off.
you should check egr valve and check for a vacuum leak
Fuel Filter? Air Filter?
that would probably be the transmission. It may not qite be working right.
Not downshifting properly Plugged catalytic converter Needs tune-up (new plugs)
alternator could have gone out running the battery dead.