I have no experience with BF but just wanted to offer you some support.

I think you're doing or have done everything you can to give yourself the best chance. I was going to suggest classes as I did one just a couple of days ago and it's given me enormous confidence. I think that the more you focus on what happened last time, the more impact it'll have on what may happen this time. Like you said, you need to let it go - all those things that happened to you last time were just nasty, dumb, bad luck events and nothing to do with what you did or didn't do. So there's no reason to think that they'll happen again this time.

I wish you the best of luck and hope it all turns out well for you.