Therapeutic target is E2=22pg/ml.
With E2=11pgml, you would reduce your 0.5mg EOD dose by a factor of 11/22
You could have skipped a dose then resumed at the new dose and things would be decent in a week.
On your prior cycle dose could have been 0.5mg/day X 8.6/22
Anastrozole is a competitive drug against T at aromatase reaction sites. Anastrozole dose depends on serum T levels. It takes a while for TRT guys to get dialed in, but then they are set. When you make changes to your cycles, it is a new game and some things will affect the liver's ability to clear estrogens and that changes the balance too.
As you can see, T levels matter. Anastrozole needs to work against steady T levels. Injecting once a week is wrong and then lab results are largely driven by lab timing. You can inject T twice a week and take anastrozole at that time and T and anastrozole levels will roughly rise and fall together and maintain some semblance of balance.