I started suffering with crippling anxiety and waves of dread/fear totally out of the blue this time last year. Absolutely no reason for it, except there is a strong history of early menopause in my family and I have always suffered with PMS.
The anxiety kicked in at roughly the same time I noticed my periods were much lighter and my cycle was slightly shorter. Some days were horrific and I just wanted it to STOP. A lot of buses rush past our house and sometimes I would think about walking in front of one, just to make it all stop

It took a lot of GP appointments before I was finally referred to a gynaecologist who diagnosed me as peri menopausal on the spot.
People talk so openly about the hot flushes and weight gain when you're peri, but very few talk about the anxiety and fear/dread that you can also suffer. I had no idea that anxiety and feelings of despair were so common with pre menopausal women.
I am so glad you have found an HRT preparation which has really helped knock your symptoms on the head. It gives me hope that HRT might do the same for me. can I ask which HRT you take?
As others have said, I would try to return to work firstly on a part time basis. Perhaps use up some of your annual leave entitlement if your boss is being tricky? Far better for you to have a slow but successful return, than to rush it too much and end up signed off again.