Hello Alfred.
I have not been in your situation so I can't give you any advice from previous experience.
However, like
>>2, I believe you shouldn't give up. Live life freely. Regret will only bind you to the ground.
Though you don't know if your brother will forgive you yet, you should become someone who did not waste their life in regret. The accident was no one's fault. It's called an accident for a reason.
Cutting yourself will not help the situation. Find someone to help you with your addiction to cutting yourself. Your brother would not be happy to see you doing this to yourself.
But, there is no point in us telling you anything if you won't accept it.
Forgive yourself.
Live freely.
But never forget you brother.
I understand you love him dearly.
He will definitely feel the same.
Live in the hope of his awakening.
Nothing will come from such a negative state of mind.
Be positive.
Be optimistic.