Isn't that the truth. Doubt (and regret) has been my constant companion for a long time.
That only shows that you are a caring considerate person.
You assess yourself. Sometimes you do it where you don’t carry all the blame, and sometimes you assess more blame to yourself than you should.
While this causes a lot of pain, at least you’ll go through life actually feeling, while others praise themselves for not feeling and being outrageously clueless.
All the best to you.
BTW: You can’t change a thing in your life, but where that next foot is placed. Choose well, and live in peace.