If you're good with isolation, you may find the hardest aspect is coping with your crewmates (or more likely, one or two of them)
If you're not good with isolation, they may be the least of your worries.
I learned quite a lot about the importance of being tolerable, as well as the more usually mentioned importance of being tolerant.
If you're a highly strung person, the former will probably require finding some way to be more relaxed, philosophical, and fatalistic. And not to take things personally. (Especially, but not only, things which are not personal)
Being more tolerant requires finding some other way than bottling things up, or blurting them out. Not easy, especially given today's cultural norms.
If possible, find someone NOT on the crew whose shoulder you can cry on.
Failing that, write it down, then THROW IT AWAY or at the very least post it to yourself, at home, marked "Personal" ! (then
throw it away, unread...)
I was lucky because my first skipper
had an astonishing ability to assess people's social compatibility. We started the trip with four watches of three people, which was soon reorganised to six watches of two people.
Both times, virtually everyone was DELIGHTED to see who they'd been put on watch with. And some of us, the skipper
had barely met before the trip started.
My biggest regret was that (being young and foolish) I relaxed my efforts to be the best possible shipmate on arrival at the interim destination
where I was to leave the boat.
I was transitioning back into my habitual autonomy, rather than remaining a footsoldier doing what he was bidden, and as a result I was a bit too wrapped up in myself to do what was best for the skipper (who had a lot on his plate) and the boat - minor incidents, but I didn't leave my reputation quite as unblemished as I could wish.
The skipper's job, particularly on a big boat, is hard enough that it pays to put 110% effort into being a truly cooperative member
of the team, for the entire duration of the passage.