I am so sorry @Wobbles, I feel for you 🤗
It is awesome that you are trying to exercise even with all that happening, you must give me some inspirational tips 🥰
I am afraid I have no advice about HRT, but can share what I do when my feet get puffy. I found that ankle brace support worn for half a day or even a couple of hours helps me a lot and feet don't return to their puffy state for quite some time after. If you get some thinner ones, perhaps you can even wear them while walking?
I think this edema can contribute to pain in your muscles, mind you I am not a medical professional, this is just from my experience.
In terms of walking shoes, Go walk and knock offs cope well with everchanging feet
Go easy on yourself, our body's are changing, we had hellish couple of years. Important thing is to try! And do contract your GP, your health and happiness matter 🤗