whenever i do this kindof strumming thats played in the beginning of this song http://youtube.com/watch?v=XKOwGffqlbM i can play it for a little bit but then my arm gets super tired and it gets sloppy so i figure im doing something wrong. Any ideas, or tips? and also im terrible at tapping any tips and/or some placest to do it at ???
You've heard a like a broken record. PRACTICE, PRACTICE, PRACTICE! And that's wat you need to do. Build up those muscles, man. It works, trust me.
I haven't heard that song in so long...

Metallist is right, with parts like that, you're just going to have to practice and find a position that's comfortable for you to play that way in.