Try to get near E2 = 22pg/ml - 80 pmol/L
You will need an AI for that.
Takes 7-10 days to feel the effects. Anastrozole half life is long enough that it takes around 5-6 days to achieve final serum levels of anastrozole. Do not make early or frequent dose changes as you will never know where you are.
But, if you feel crashed, you are an over-responder. Then you stop for 5-6 days and resume at 1/4th the expected dose. In that case you might also feel great briefly as you fall though and below the sweet spot.
As for changing oils? Any inflammation at injection sites? Skin inching or tingling?