I'm so sorry to hear of this extreme fatigue. And the feeling ill all the time is worrying. Can you check in with your doctor(s) about what is going on? Do you suspect this is caused by Anastrozole or another aromatase inhibitor? If so, talk to your oncologist about taking a break, trying a different one, or other options. But if I was in this position, I would get a full check up. What kind of support do you have? This sounds grueling.