Loosing power on hills

I have a Buick La Saber 1997, used, new to me. I was driving up a long hill and it started slowing down without change in pedal pressure. I mean a lot. I had to pull off the highway. I started again it seemed fine, then again. I had to punch it to get it to kick in and go. Then the engine light came on. Am I screwed?

Check the cats. Sounds like they’re clogged.

Cats? What do you mean?
The car has very low miles, 38,000. Has not been driven over 35 mph for two years. Could this have an impact? Around town it’s fine. Just on a long pull uphill, it boggs, then I have to feather the pedal to get it going. Plugs are good. I just checked the easy ones…
wookie

Many times this problem can be associated with loosing electrical current. Check the spark plug wires, they may be old and the current may be jumping. Your car could also be running with a sputtering jerkiness back and forth movement.

Change out the spark plug wires, as a first to do. They are probably ready to get changed out anyway. You won’t harm your car, on the contrary, there is nothing like having new spark plug wires on your car, your car will love you for it.

Catalytic Converters. Especially if the car has been putting around town for two years without ever going over 35mph. The O2 sensors in the cats probably will need attention as well. The check engine light supports this too.
Take it in and have the on board diagnostic codes read and that will point you in the right direction.

Auto or manual. Auto could be slipping. How is acceleration from a stop?

If auto, when was the last time you changed the transmission fluid?