.25mg Arimidex/anastrozole every 5-7 days is rather vague.
When you inject once a week, T levels change a lot. And E2 levels are changing to as FT changes FT–>E2 rates.
Anastrozole is a competitive drug that needs to match serum T levels. Steadier T levels are needed. Try injecting T twice a week and take anastrozole at that time. Do not change anastrozole dose frequency, change the dose. Do not be tied to 1/4mg increments. Get liquid anastrozole or make your own 1mg/ml with vodka and dispense by drop or volume.
Do labs always halfway between labs avoiding lab result changes driven by timing changes.
Injecting subq avoids IM muscle damage and provides steadier T levels.