Hi Ally,
Welcome!
Whilst I can't help you on the Femoston side ( am on estradot) I can empathise with the moods on the run up to periods. Had pms my whole life but this year they went out of control. If you are in perimenopause the extra hormonal fluctuations seem even more volatile. But, hrt can help.I am on quite a high dose now, along with a low dose AD. Initially the AD was for me to use on the run up to periods, but it made such an improvement I now take it every day of the month. I too have MH problems.
It can take a while for hrt to settle,and there may be some adjustments along the way. But for me,getting on the right regime has really helped me despite a pretty hard time getting to this stage.
Do use this forum for advice and As much support as you need. I do!