It's immature to get upset at you when you ask him what's wrong. It's toxic as well. However we give each other allowances to be crappy when we're upset. Ask him later when he isn't so upset what he was upset about. If he's toxic again well.. Maybe he actually doesn't trust you. That's not your problem if he doesn't.
It's his. And you aren't a circus clown meant to perform feats to appear trustworthy. Get your apology and ask if he actually trusts you. If there is a healthy way to communicate when upset then, that's for you both to figure out.