OP, I think this is a marvellous idea!!
I’d advise doing a week first to see if you like the concept. My mum was unsure but an hour in loved it!! 😂 She’d have stayed for good!
When you work out what you’d pay for accommodation, food, entertainment, gym, pool, etc., it’s actually ok! A few shorter cruises may be better to provide more variation on the entertainment, and facilities etc..
You can get annual insurance policies that cover cruises, I don’t know about limitations on lengths of the specific cruises though.
It sounds like you have support for the gaps, and not much to store, and it would be a wonderful experience, you’ll make friends, and like you say, a bit of a reset.
You can chose what packages to add, I wouldn’t bother with the alcohol one for you, just buy the odd drink when you want it. It’s still be cheaper that way.
Happy cruising! Please let us know where you’re going first when you’ve booked it! 😃