How to get over a failed interview?

The short answer is don't sweat it since it looks like you've taken the necessary learning out of the experience already (i.e. things that are in your control that can be improved).

It's ok (and human) to feel bad about it for awhile, but don't let it consume you. Give yourself the next thing to pursue, which is likely generating more job opportunities after you've plugged your known leaks in your interviewing skills. Turn your focus to "input driven goals" as the results are a lagging indicator of what you put in.

I wrote a LinkedIn post on job searching in a tough economy awhile ago, which may help.

I can empathize with you, the experience can be very disheartening. I think it also has a lot to do with how much we tend to prematurely invest into our 'ideal' scenario that it crushes our sense of identity or self worth when that is not realized. What you're feeling makes sense and is completely normal.

That being said, it is imperative we do not wallow for too long. Time-block your 'mourn' period, write down your self-assessment of the interview, reflect on what happened, what went well, what you could have done better, etc. Then you must move forward. The best thing IMO is to have new interviews lined up, back to back. That way, we simply do not have the time to linger in this space, feeding our ever-growing sense of self-doubt (this is important for self-critiquing but not useful right now).

From my experience, I would feel like a failure for a day at most, but I could not afford to remain there more than that because I had another interview the following day and I needed to dust myself off and get back up. Line up those interviews, and you will forget about worrying about this 'loss' before you know it. (Because) there will be new issues to work through ;).

(I just realized that I am not sure if you are trying to just find a new role or if you are only wishing to find a role at very specific companies. Even if it is the latter, I still think it will be beneficial to build the muscle by continuing interviews else/everywhere.)

It feels that landing a job is really hard, and I wonder how I managed to pass interviews earlier.

Unless you have been in the industry for 15+ years and went through 2008 and 2000, you were able to land jobs before because the market wasn't nearly as terrible as it is now. You're doing just fine - Keep it up. If you're getting interviews with companies you're excited about, it's only a matter of time until you land a great role! As long as you persist and continue reflecting and growing, your interview proficiency will eventually reach a state where they would be foolish to turn you down.

If you're feeling really bad, I recommend taking a break for a couple days, maybe even a week+. Forget that interviews exist, and do something fun! Come back recharged and eager to improve.

When it comes to preventing the same dejection in the future, I recommend these 2 strategies:

1. Always subtract 20% from your guessed pass rate - So if you think you had a 100% chance of passing, it's 80% in reality. If you're initially thinking 70%, then it's really 50% pass chance. From my own experience and coaching several others through job searches, this 20% deduction works for the vast majority of cases, preventing you from skyrocketing your hopes up unrealistically.
2. Stop caring, be more chill - While it's true that passing an interview and getting an offer is a potentially life-changing opportunity, it's important never to see it that way as it just leads to stress before, during, and after the interview (if things go poorly). It's much better to treat it as a learning opportunity instead, which I cover here: Having The Proper Mindset For Interviews

I hope this playlist helps as well: [Taro Top 10] Effective Interview Prep

Thank you all! That helps :) Feeling a lot better now after reading the comments. Will keep a growth mindset and not take things tooooo seriously :)