Sometimes you just have to make a blind leap of faith, and trust in the Universe. I realize it's a trite thing to say, but just remember: When one door closes, another opens.
You will be just fine. We've all been there and experienced retirement in different ways. I jumped in with blind faith and never looked back. Fireboy planned and fretted and budgeted and worried and second-guessed himself. And he has never been happier.
I bet 99.9% of us are so happy to be retired.