"was told to persevere as side effects reduce after 3 months"
Which prog options have you tried before btw?
Its really important to give things the 3 months

I did the same as you and was all set to throw mine in the bin during the first month or two.
However with support I was able to get through and now I'm glad I persevered.
Stick with something and give it time.
In terms of where your at, are you still having semi regular period's?
If so then perhaps your just doubling up on your own progesterone thats still being produced.
It might also be associated with your low dose AD, that can also have an effect on things.
The other option you could try is Tridestra.
This is estrogen mainly for 3 months then prog is given at the end of the 3 months to start a bleed.
This might give you more time to see if prog is actually part of the problem here.
As it may just be your own cycle still cutting in and making you down.
For the sake of giving this a few months or a slightly different option you might avoid a major life changing operation.
Hope things improve soon.