I've been playing guitar for a couple months now so I'm still very much a beginner. I feel like I'm making alot of good progress when it comes to playing songs that use individual notes and melodies, but I'm having trouble playing songs that use chords. For example, I looked up the tablature for a song that I like and I found out what chords it uses. It starts out with a G chord, and then goes to Em. I've gotten pretty good at playing those two chords and I can even switch between them pretty easily, but no matter what I do, it just doesn't sound like the song I'm trying to play. I think its the strumming pattern that I can't figure out. Or I think that maybe the artist is putting more emphasis on certain strings. Whatever it is, I can't figure out how to emulate the sound. It's beginning to frustrate me because I feel like I'm making no progress when it comes to playing songs that use mainly chords.

Anybody have any suggestions for me? (By the way, the song I'm trying to play is by Ryan Adams, Damn Sam)