There are so many courses online, it would be hard to suggest some over others. I've heard Udacity is pretty good.
As far as feeling ready, I don't think I ever did feel ready before applying. I left every interview feeling like I hadn't learn anything, but that's because programming is such a HUGE field. Even at work, I'm constantly reminded of what I don't know - but I welcome the feeling now because it is an invitation to learn.
So if your absolute goal is to land a job, then if you don't land one when you expect, you may be tempted to give up. BUT, if your ultimate goal is to keep learning (and have landing a job be a product of that), then yes, interview rejections may hurt, but they won't keep you from pursuing your goals.
Hope that helps!
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