Probably around 28 drops per ml for that product, check if you can somehow. If so, then 8 drops EOD will be 1mg/week. Try that and expect to have some good effects in 7-10 days. You can do E2 labs in 3 weeks then adjust dose as per stickies. At 150mg/week we would expect that you would need 1.5mg/week. If you feel good at 1mg/week, you can try 1.5mg/week and see if that feels better and you might try that before the labs.
However, it can take a few weeks for your brain to adjusts to the lower E2 levels as many processes are involved and your brain patterns will also shift and it takes a while to reach an end point. I guess the key observation would be if you increased the dose and then felt that things were not as good, it that happens and you need to revert to the prior dose, stop anastrozole for 5-6 days then resume at the lower dose.
Most of what you need can only be obtained by more reading and study. Please read the advice for new guys sticky. There is an estradiol sticky as well, and for finding a new doc if needed. Also note the protocol for injections sticky.
Your experience with lost gains is typical. Lowering E2 should be transformational. As your brain patterns are changing, it would be helpful to have a positive attitude and that may be engrained into the final product.
Please post more info as per the advice for new guys sticky, perhaps we can find the cause of your low T.
Did doc test LH/FSH before TRT?