[Question] How the hell do you people do this?

Hello, I would consider myself a decent pianist, I think piano is incredibly easy. Obviously I'm biased but anyone can make beautiful piano sounds by just pressing keys down. I'm a huge fan of guitar though bc I love rock.

I picked up my old guitar today (I played for a couple years in middle school) and I'm trying to play Funk #49, but my GOD is this interrupt the hard. So to play this song, you have to only strum 3 strings repeatedly, do hammer ons without touching the other strings or it mutes it, and all the while it hurts like hell. Are there tricks or something because this seems impossible to me.. Are there tricks to fingerings and strumming that I'm missing?? Much respect to you guitar players out there..