Good luck with your move to the boat! I hope it helps with your mental health issues. Mental health is such a neglected and misunderstood field of medicine, I hope you are able to find good help for your problems.
If you are going to spend time on the boat by yourself, I'd recommend that you find a canine companion. Dogs are really great listeners, and, when you think about having a session with a psychiatrist, the dog is actually a hell of a lot easier to talk to, and infinitely more understanding than any psychiatrist could ever be.
Just my two pence worth......
Whatever happens, good luck with your issues - I really hope you eventually feel "whole"!