I was recently trying to learn these tabs for a few days now and for some reason it's just not sounding right to me. It might just be my strumming or how I'm playing it, but the C(add9) just doesn't seem to fit in with everything else. Am I just terrible at playing or is it the wrong chord? Someone please confirm

Oh, by the way. A link to the tabs: here

I am going to try and find a link to the song so those of you who haven't heard it can hear it, but for those of you who are familiar with the song, you can start the analysis now
So I am thinking it is just a normal C instead of C(add9). I would appreciate any help at this point. It's driving me crazy as to which is right