The part where they said ignore symptoms. This was back in 2007. There was a diagram of some sort on the floor and I was supposed to walk around it, I can't remember very well, and something about saying "stop" AND ignoring how I felt. So when I did all the things they told me to do and I could feel myself getting tired, I forced myself to ignore how I felt and I crashed of course. I literally could not do what they told me to do without crashing.
I do meditate on my own - I've been doing it for many years and it doesn't have the paradoxical effect it has on you - that's unfortunate that it's problematic for you!
One other thing you might try to calm your system down is box (or 4-sided) breathing. It is amazingly effective. It's used by police and Navy seals and firefighters, people in high-stress positions. It's also used by people like me too!
Box breathing: How to do it, benefits, and tips (medicalnewstoday.com) It helps put me back to -sleep in the middle of the night or if I just need to de-stress during the day, it's quite effective.
The instructions say to do the 4 steps to a count of 4 each, but I've found it to be more effective to do the inhale for a count of 4 or 5, and then the other 4 steps to about a count of 8 each.
One other technique is to inhale slowly (through your nose) to a count of 5 or so, and then exhale (again through the nose) slowly, for a count of 8 or so, and just repeat.
All of the exercises are done with your mouth closed.