I can't see any "what ifs"in this situation. If you feel you have to learn from your own mistakes, why are you asking for advice?
I think you know why. You know this is self destructive and all the sympathy you get from any source will never turn your situation around. It will only hurt you more. As for once being a self harmer, I see this as a good way to get back into that behavior. No one wants that to happen to you. Your cry for help has been heard and I commend you for that.
Everyone has tried to help you. You are on page 4 of people giving you very good advice, but you are right... in the end you have to live with your own decisions.
I hope that you soon see the hopelessness of trying to change anyone before they are ready to change. That alone will help you get thought many of life situations.