Q: Recently when I press the gas half or more of the time it really struggles to get up to speed.

A week ago I drove on the freeway for about 45 minutes in drive 2 on accident. Ever since then, when I press the gas it takes a super long time to accellerate. I took it to the auto repair shop first, and they sent me to the exhaust gentleman across the street. He chopped off my cat and put in an exhaust splicer, and that COMPLETELY (I strongly emphasize completely) fixed the problem for precisely one driving session. The next day it was doing the exact same thing again. I just got back from the auto shop for the second time and they said they thought it was bent lobes on my hollow camshaft, and sent me on my way with a death certificate for my car. My question is, if that part was broken, wouldn't the problem still have been present when he took off my cat? Or could that be causing my fuel to burn incorrectly and that's the problem? Any ideas you have would be very welcome, I'm just trying to hang on to a thread of hope my car isn't toast haha. Thank you!

My car has 120000 miles.
My car has an automatic transmission.