Pre-bleed progesterone levels drop sharply - giving rise to pms symptoms in many women (headache, irritability, anxeity, depression), but in addition oestrogen levels also fall to their lowest and it is this that is thought to be the major cause of the low mood element of pms and which Prof Studd (amongst others) treats with oestrogen.
It may well be that a low dose of hRT could help at this point - to reduce the oestrogen dips anyway. The problem is when you are not quite at peri-menopause yet (ie periods are still regular) too high an oestrogen dose can apparently give rise to high oestrogen symptoms in some women (not low mood though - women talk about jitters - but not experienced this myself that I know if) - because there are oestrogen highs as well as lows.
If you were younger then a type of contraceptive pill with oestrogen in it the same as HRT could be advised - as it controls the cycle - but I'm not sure a specialist would prescribe this in your case due to age (50 appears to be the limit). Might be worth asking though as you have specific requirements re hormones? The product is called QLAIRA and would stabilise your hormones to some extent - although the oestrogen dose is variable, but there are onlyu 2 tablet free days.
There is another called ZOELY with more tablet free days but an even dose of oestrogen, which might also be worth considering if a consultant would prescribe it post 50. Can you ask for a referral to a gynaecologist/menopause specialist who will take into account your mental health history?
Nick Panay also specialises in PMS and is available on NHS in London (as well as privately) and there are other gynaecologists here geographically listed:
http://www.menopausematters.co.uk/clinicfinder.phpHurdity x