OK I did some research and what I found turned out to be no cheaper than what you've already found.

But here's what I found using the advice from @shenanigator's post

Since your dates are flexible you could start travelling on Thursday morning 10th November and take 3 different flights to get to Amsterdam by either 2pm or 6pm (depending how much time you think you need for the 2nd layover) on Friday the 11th.

https://goo.gl/flights/4LiU
The above link displays a connecting flight from DFW Dallas to YYZ Toronto and an overnight flight to LGW London.

This would have you arrive in London for 10am (take into account possible delays) and from there you could choose one of these flights with British Airways at either 11:40 (this might be risky if you have checked luggage to college and check in) or 15:45 which would get you to Amsterdam just after 18:05.

Flight costs

Dallas - Toronto $171.79
Toronto - London $261.66
London - Amsterdam $108.21

I stopped when I got this far because I realised it's not any less expensive than what it seems you've hunted down yourself. These flights are all a bit cheaper if you leave a few days early. A few days to explore amsterdam before the steem parade arrives could be worth it and your experience would be valuable to the rest of us just arriving as you can scope the place out before we get there ;)

I really hope you get the support you need to get your ticket soon, I will try reblogging your daily Yoga posts.