Hey Nas,
Focus on that positive point. One step at a time, get the Mirena out first. I doubt you would be able to go back on hrt without an adequate progesterone for protection. This needs to be discussed maybe at the point of coil removal.
You have your appt in the offing as well. I am no ex pert, so someone please jump in here, but do some women not take oestrogen only for a VERY limited time whilst sorting progesterone?
I realise this could cause a further imbalance, with too much oestrogen, and of course no progesterone over a longer time could affect thickness of womb lining.
My advice such as it is, is don't panic, things are happening. coil removal due, appt 're fibroid due, then time to sort your be st hrt needs.
Hang in there girl, things are moving in the right direction. X