Don't loose faith. With a single company giving feedback, you probably got already 50% of all feedbacks you can get. Your effort for asking all the others was already worth it.

On top of that, most of the feedback will reflect what state the company is in or what kind of people they are looking for, and not necessarily you or your skills. Eg. they want a deeply technical person, or a good communicator. In one year, for the same position, they will want a different set of skills.

If you know a lot of prospective companies, experiment with your CV / introduction and try to A/B test what is working. This is totally under your control.