I read everything that I could find on anastrozole, including hours spent on Google Scholar, and haven't seen anxiety mentioned as a side effect. Anxiety is sometimes triggered by menopause, e.g., lowering estrogen levels, so maybe a consequence of that effect,, but that tends to decline. General anxiety levels certainly increased from covid, lockdown, political polarity, inflation, etc.

And you're dealing with more than one issue personally so that's a challenge too. I'd review the meds you're taking with your PCP and maybe pharmacist as well to see if there are any contraindications or anxiety side effects. But also realize that you've survived a lot and sometimes the body experiences delayed anxiety as a kind of relief and safety valve. If that sounds possibly explanative, you can put it in perspective and gain distance from it, while doing a lot of self-support stuff like meditating, nature walks, drawing, and other activities to kind of stay grounded in the present that you can control. It sounds simplistic but can be empowering.