There has been a lot of good advice and info offered here. I would like to just add this:

If you don't need to retire and you have a bunch of questions or doubts of the kind brought up by the OP, my sense is that you're not ready to do it yet and you probably shouldn't. When it's really time to do it, I think that you'll know it, not just suspect it.

Disclaimer: These observations are not backed up by personal experience. I was ready to retire as soon as I was eligible, did it, and haven't regretted it for a second.