Demand side: It is way too early for you to be saying that you are not going to get anything in the market. You wrote that you had some good interviews. Not much has happened with lower ranked schools yet. So, stop being so self-defeating, yet.
I have some students in the market who are in the same situation as you and they are just standing tall, waiting for things to happen. We are also in the market and we have not even had any flyouts yet.
See if you can learn from your mistakes from this past flyout and try to do better in the next ones. If you get too nervous, there are several tricks you can do, but I can't write it here over the internet. just google stage fright tips or medication, etc. Focus on getting better at interviews and at giving seminars for the next opportunities.
You think that is brave of you to say that you are a failure. It is not. I learned at a young age that when life does not give you something, YOU TAKE IT. Go for it. The world is going to try to put you down. You are the only person who can lift yourself up. This is brave. If you do not believe in yourself, you have no business being in a competitive setting. I can tell that you are competitive by the intensity of the frustration you are feeling -- it is a sign that you have a lot of inner strength. Use it for your own good, not to defeat yourself.