I hope this set of videos has been helpful. You will get there if you just keep focused and keep trying. As I keep mentioning: it's likely you won't make it through on your first try... these interviews are tough!
What you're going through now will be the stuff of fun stories later on - just focus on keeping a positive mindset. It's sooooo easy to let the frustration take you over, making you want to throw in the towel and give up entirely.
Please don't. These interviews are hard for a reason: the jobs pay well and some of these companies are the best to work for in the entire world. These jobs are amazing - it's not easy to get in.
You might have to try three or four times to make it in... but it's worth it and you can do it. You really can. Good luck to you, and stay frosty!