Hormones can cause great upheavals. Dr Dalton did a lot of research and studies with regards about PMT , she represented women in Court that had committed murder during their pre-menstrual hours.
The National Association for PreMenstrual Syndrome - NAPS - might offer support and give advice.
Hysterectomy is major surgery. Consultants rarely give HRT advice prior to surgical intervention, nor do they follow up enough !! Your whole system may be in shock, it may be a form of PTSD. A therapist au fait with this would be essential.
...... and breath. Some find that yoga or meditation helps. 'me' time. Swimming? Gentle walking?
MIND have walk-in centres if you feel you need somewhere 'to be' if you feel unsafe. They also kept in touch with me when my friend died suddenly, I didn't get to the office but they sent regular e-mail updates.
We are here and listening!