Have you read the protocol for injections thread?
You can carry on with your old T dosing if RBC and hematocrit are good.
You gave mixed signals. Need lab work at some point.
Sounds like lower E2 is good for your erections but bad for brain/energy.
Try less anastrozole.
Going from E3D to E4D may not be enough.
I agree about feeling that dose is workable before doing labs.
A dose change takes 6-7 days to lead to steady anastrozole levels, so you can't rush this or make multiple fast changes.
Anastrozole and E2 should not affect thyroid function.
You can monitor oral body temperatures when you wake up and mid-afternoon as thyroid dosing guides. Look for 97.7 or higher in the AM and 98.6 in the afternoon.
See thyroid basics explained in 2nd post of 1st forum topic in T replacement forum.
You should try to get fT3 and fT4 near midrange and this may push TSH very low.
TRT can lead to problems with low thyroid function when thyroid function does not support metabolic capacity to manage the restored metabolic demands of TRT. Ditto if cortisol is low.