European sizes are indeed a lot smaller than American sizes. It's an honest mistake, really, so I wouldn't worry about it too much :) I tend to really agonize over sizes when I order t-shirts online. They usually have size charts, and I end up measuring my width at the shoulders and my torso height XD It's a lot of fun.

Nice vlog! I'm sure with time you'll get less nervous and appear to speak more relaxed and everything, so... that's cool.