Just live normally. You'll be better off if you can catch some fish. Dig up the caves so you can set sail whenever you need to. It wouldn't be easy. But you have an endless amount of time ahead of you.
If you could see everything but couldn't change any of it, or if you could live in freedom in darkness... Which do you think is more fortunate? I think it might not be that bad living in the dark, remembering the light.