I have been through something similar, but I did have a job and some income. You definitely need to find out about income, finances, assets and liabilities etc and then see a solicitor, who will then advice on your likely entitlement. 50:50 is only the starting point and not necessarily the finishing point especially as both parties needs and earnings potential are assessed. Once you know where you stand, then consider your options based on your means. Where you are going to live and what you have to live on are essential, particularly when you are over 50 , as there is less time to be able to earn any money to get back on track.
If you decide to end the marriage,you may initially have emotional turmoil, guilt, anxiety and depression. My menopause was also difficult time, but for me, the light at the end of the tunnel was brighter than the darkness in my marriage. Counselling may also help. It's also worth taking up some hobbies and outside home interests, and building or rebuilding a small network of reliable friends to support you if you leave.