I'm sorry I asked you out. I'm sorry we dated. I'm sorry I wanted to be with you.
Are you okay?
I'm sorry. I'm sorry I'll never be good enough to fulfill your expectations.
Being upset that we aren't together anymore is fine but you shouldn't be apologizing for being yourself. Don't beat yourself up over what happened. You should be trying to use the past to be better in the future instead of dwelling over it.
I'm sorry, I'm used to everyone judging me.
You aren't being judged, but it sounds like you are ready to make some changes in your life. Use this situation as a time to grow.