I've uploaded my video sideways, is there any way to fix it?

[AC Question]

I spent ages filming my first video, after trying a couple of different filming apps I chose reShoot, I filmed sideways on my iphone and then (after a little trouble) I managed to upload it onto Youtube, when viewing it, however, I saw that it played sideways. I am upset and confused, is there any way I can fix this short of filming the entire thing again?!!! All help appreciated! X

 

[LeoRex]

You can do this directly in YouTube now. Go to video manager-enhancements. The option to rotate should be there