Hi go easy on yourself!

you've been bereaved. I take months sometimes to grieve. It will be something unrelated that will trigger tears.
HORMONES

how were you during your menstruating years, irritable B4 a bleed for example? Make sure that you eat little and often, gentle exercise ........
How close are you to your sister, could you meet for a coffee and talk it over? The written word is static ........ is she bereaved too?
Regardless of your Mum's diagnosis: which may not be oestrogen related anyway. Maybe make a list of which symptoms you feel could be eased and discuss with your GP/Practice Nurse?