The title of this article probably sounds really insensitive but it is definitely justified.

I have recently found myself feeling like I need to say sorry to people just because it's the expected response. But then I realized, what is the point of apologizing for something just because someone wants to hear it?

You don't need to say "I'm sorry" just to help someone else's pride. Stop apologizing for things that you feel you didn't do. It may seem rude or even petty, but it's a waste of energy.

Your feelings are justified and you don't need to sink to someone else's level because they want you to. I've learned to put my own thoughts and feelings ahead of obligations to someone that they think I have. I will not apologize for things that I do not feel responsible for to appeal to another's dignity.

Basically, the message I'm trying to send is that you should always put your emotions ahead of others'. It's not selfish to leave a friendship that is no longer benefiting you emotionally, or to hold your ground when you know you are right. Stop apologizing and start listening to yourself.