Im having a really hard time with my accelorator on my tracker

What is your question?

Ok so I bought my tracker, single owner and it has 128k miles on it. I took two trips, both about 1k miles each, and on the return when I was almost home the check engine light came on and the accelorater started fighting me, and I had trouble accelorating, and I have a real hard time getting past 45 mph. Im not really mechanically inclined, but Ive searched the web and I cant find any answers, would anyone happen to know how to fix it? Its a great car, I really want to get it fixed.