People don't leave because the job is bad, people leave because of bad managers.

Unfortunately, you've got a really bad manager.

Don't take it personally, even though it looks like he's after you specifically. He's clearly a prick on a power trip and is interpreting your maturity and respectfulness as weakness, and that's really horrible. I'm really sorry you're going through this.

Don't let this bad experience erode your personality. You're not too sensitive - you care and are empathetic and that's huge.

If you can, try to find another job. Chances are it'll be much better than your current situation.

If you can't, try to distance yourself, internally, from that horrible manager. He'll say whatever he wants, it doesn't mean you have to listen, you can just look like you're listening and leave it at that. It's really unfair.

You might not be able change your situation but you can change how you relate to it, and that's easy to do with someone that's focused on superficial appearances.