That sounds like a really crummy work situation. Having an abusive boss can do an insane amount of damage to your self confidence. I was in a similar situation five years ago and endured rather than leave.

In hindsight, this was a mistake. It's been a few years since I left and I still sometimes have nightmares about the place. I wish I had started looking for another job as soon as the abuse started.

I highly recommend going on interviews. It will either make your current work situation look better or offer a possible escape. It's pretty easy to keep your job search a secret from your boss.

I also wish I had used the time I had at that company more productively, i.e. that I had developed more skills or asked for company paid training that I could list on my resume.

Would it be possible to talk with your first boss about how to deal with your current boss micromanaging you and how your work suffers because of it?