That other person who thinks that you're all drama, is not better than you and his or her opinion of you, is just that -- an opinion. And, this person's label of you, is their attempt to marginalize you for some reason. Don't fall into their trap.

If he got annoyed with you b/c you shared information with him about what you overheard, it's because he didn't like what he heard. Ever hear that phrase, "please don't kill the messenger?" Your situation reminds me of that phrase. It's a metaphor for the person blaming the bearer of bad news for the bad news itself, as if the messenger is responsible for said bad news but that's not true at all. Playwrights have been writing plays about the messenger being blamed for bearing bad news for centuries. It's a common trap that people fall into, when they get in the middle. So, easiest solution: let people work out their issues with each other instead of involving you.

The next time a friend comes to you with information about another friend, stay out of it. Don't show any interest in helping this friend solve their problem with your mutual friend. Gossip is a social bonding exercise amongst groups of people but it can also ruin friendships and be used a social tool to manipulate friends who are perceived as naive, gullible or weaker than the manipulator.

Don't stop speaking your mind or being direct. Basically, don't change yourself to constantly please other people or you'll find yourself constantly in a state of exasperation, because you literally can't please everyone all of the time and should stop trying to do that immediately, because it's not your job either. Just be yourself.

If being the middle man, the bearer of good or bad news with others brings you negative results, stop sharing information, i.e. stop gossiping. Third party information is a form of gossip, mal-intended or innocent. The person you share the news with, will always view you as a bad person b/c he/she won't be able to separate you from the news or information you have to share with that person. Stop getting in the middle. Let people figure things out for themselves. Ok?

And keep your job interview. Those golden opportunities are rare and few and far between. If you give into your anxiety now, you will regret it for years to come.