Responsibility and accountability.
It doesn't matter if you've done nothing wrong. Their mistakes are yours. Their failure are yours. You've done your part, you gave your best, but in the end, you're the one to blame. Every error is your fault. Despite your non-existence when it happened, it's all on you.
Admit it. Ask for forgiveness. Beg for another chance. Keep on striving. Never give up.
A little bit of pain is necessary, it will lead you to that one true love. Everything will be worth it. If it's not okay, it's not the end.