You can never say "I am sorry, I didn't mean to do this" with enough conviction. How do you put it into words convincingly enough for the other person to understand?

I've been impulsive and selfish yet again. I wish I could articulate that I'm not a bad person and I'm just a bit immature, incapable of making wise decisions at the right time?

My solution?
I won't be impulsive in the future.

I was better off not being responsible for another person's feelings.

I'm not fit for relationships. And I am trying to say this with the least amount of self pity. I mean every word.

No more. No more of this.