I'd like to suggest some suggestions for getting past the first interview, from the highly tactical to the truly out-of-the-box strategies (which I happen to prefer)

When you don't get a second interview, follow up by email or phone and just ask what happened. Make it clear that you're not questioning their decision or trying to change anyone's mind - you're just looking for feedback to help you improve your interviewing skills. Not everyone will answer, but some will and you might get enough information to start making some changes.

Don't think for a second you have to put up with bad behavior from your boss. You don't. Sure, your boss will have her own priorities, workload and personal stuff going on, but she still needs to treat you with respect and as a valued member of staff.

Hmmm, sounds like the honeymoon is over and your boss’s true colors are blazing! Living in terror is clearly a sign of an abusive boss and you’re the one who ends up paying by taking hits to your self-esteem, productivity and even your health. You didn’t say, but like many targets of workplace bullying, you may have used “mental health” days to recover from the ongoing stress.