Everyone is different and reacts differently to things, but I am your same age and faced the same things recently. I do not know whether I am in peri or full on menopause, as I've had a hysterectomy (still have my ovaries), though I've had no symptoms.
Regarding stress, I actually took on LESS responsibility at work. I decided that it is time to focus on my life outside of work. I was tied up in knots over that decision, especially because work had specifically asked me (which was a major compliment) to take on MORE responsibility. But I have never been happier. I work the hours I work and that's that. I don't worry about the politics of the building (they exist everywhere) and keep my nose out of where it doesn't belong. I keep my work life separate from my personal life. Best. Decision. Ever.
My youngest child left for college in the fall, and I was TERRIFIED of the empty nest. I really didn't know what I'd do with myself. My situation is slightly different in that my 22 year old son is living at home, but he is working full time and is gone most of the time - at the gym, with friends, etc. My second son visits from school sometimes on weekends, but my youngest is gone most of the time.
The reality? Dh and I have connected in a way hwe haven't in YEARS. We are closer than ever before and we're both loving it. Of course, we love when the kids are home, too, but I am unexpectedly loving and embracing this change.
And I know how hard it can be, but sometimes you must distance yourself from those who depend on you emotionally. Sometimes you cannot be the pillar for everyone else and still keep yourself standing. Take a break, be unavailable sometimes and step back. You can decide when you feel less anxious about how close or how distant you want to keep said people in the future.
Good luck, and I am sorry you are going through so much. Meditation is a big help for some people, too.