Sorry you are having to deal with all this -- sounds incredibly stressful. I understand that you feel you need a break, but do be mindful of your long-term financial stability as well. Personally, I would not be comfortable relying on someone with a serious mental illness for the next 10+ years financially. Understand that you might not have the energy to take on full time work at the moment, but do consider what you can do to bring in more income on your own so that you would not be devastated if you lost the financial support of your spouse at this time. Also consider putting some time limits on the financial outpatient support to your kids. I understand that you are wanting to help them out and be sure they can launch successfully, but they should also understand that your support cannot be unlimited in either amount or duration. For example, have you considered the possibility of downsizing your current home, and what that might allow you to add to your retirement stash? It might be substantial. If that is the case, then you might want to let all of them know that Hotel Mom is probably going to close up shop in 1-2 years, and they will need to have a plan for living independently before then.
If you can get to a situation where your dividend and interest income is sufficient to support your own basic living expenses, that would be ideal. Will investing the $400k in Wellington/Wellesley allow you to do that? If so, then perhaps downsizing is not necessary. If not, then I would be thinking about it, as well as additional ways to generate income. Note that offering to babysit for parents at the preschool where you substitute, if allowed, can be a great way to generate extra income with minimal stress -- I used to do this for one family when I worked in childcare, and it was great. I really liked their daughter and they paid me about $50/night back in 1990 --would probably be more like $100/night these days.