Stop blaming yourself for everything that goes wrong in life! I have learned that it is NOT ok to accept being the bad guy in a situation, all the time! It came full circle for me to learn that people needed someone else to be that “bad guy” to make themselves feel better and that is not ok! It will wear and tear on you mentally.
Accepting and owning up to your mistakes is a major maturity event. Both sides of an argument have to do that! Sometimes mediation from a “voice of reason” can help alleviate the need for a “bad guy”.
Once you own up to your part, then let it go! From that point forward if the other person does not do the same, just move on and forward. You did your part and your conscious is clear.