Eminem "Space bound" music video?

i watched the "space bound" music vid by one of my favorite rappers Eminem, and it's cool, the only thing is that i dont get it! im the type of person that likes to understand and get the deeper meaning...i've rewinded the video plenty of times but i cant figure out why there's two of him, and why he choked the girl out of nowhere? can you break the video down for me? thankyou(: a href="http://www.youtube.com/watch?v=JByDbPn6A1o" rel="nofollow"http://www.youtube.com/watch?v=JByDbPn6A…/a