Sorry about your situation. Maybe your principal thinks he or she is helping, but that would be extremely frustrating. Does he or she actually expect you to implement the tweaks that lesson, or can you just implement in the next lesson plan?
If you can go to a MAX teaching workshop, that is the thing that was the light bulb for me. Lots of research based and proven plug and play kind of learning activities. It's one thing to get Forget's book, but it's another to go to a workshop and have the activities modeled. I use it in every unit / learning cycle I teach
https://www.amazon.com/MAX-Teaching-Reading-Writing-Activities/dp/1412009928