u/AlternativeNo6487

PLSSSS HELP. Ive had this car for about 2 1/2 years now. Over the last few months i’ve had the check engine light come on and off. The car still started and drove fine. I got a few codes and did a 02 sensor clean that seemed to keep the light off. Earlier this week it came on by Wednesday it was off again so I didn’t really think much of it. Friday I drove it to work, home, drive one town over and it felt fine. On the way back home I could tell the car was struggling. Not accelerating, Rpm’s still going up just not getting speed. I now live on a big ole hill tried to come up and it made it put it was working really hard drove around my building and this what it sounded like going up a much smaller hill. IM willing to get my hands dirty and put some work into it , I really don’t want to spend a couple hundred at the dealership. Does it sound like a bad catalytic converter?? What could it be? Is it a hard fix? Is the car done ??? please any answers or guidance