Regarding vacation:
Take your vacation. Don't agonize over it. You need to put yourself and your health first. I was a very conscientious employee and (in hindsight) realize that you should always maintain a healthy balance between work and personal.
If your boss is aware of your health issues, she is being very selfish in trying to manipulate you into foregoing vacation.
Reality check: If you died tomorrow, the workplace would continue to operate.
I also learned from personal experience and observation that it's not a good idea to socialize with someone who has decision-making power over you.
Interaction of that sort is what led to the necessity for workplace harassment policies.
You can have one-on-one lunches occasionally with your boss but the less each of you knows about
your private lives, the better.
For instance, suppose you went out with them and her husband says something or acts in a way that embarrasses her. She could then feel uncomfortable about
you and it could affect your work environment.
Maybe others can offer practical advice about
how you could tactfully refuse to socialize in the evenings and confine it to an occasional lunch.
You might blame it on your significant other who prefers your "exclusive" company.
