When you decided to leave for others, were you ready to lose your own self-worth just to make other people happy? Running away from your childhood friend after finding out that he's not the person you've known him to be is one way of preserving yourself. It is also an indication that you want something better for yourself and staying with a drug-damaged and dying person will not be good for you. I think leaving him was a good decision because you realized that he was too focused on himself and he was using your guilt to make you stay with him. He's dying yes, but that's not reason enough for you to endure his treatment of you. Just let him be as you cannot help him anymore. Focus on what's gonna be good for you to help you recover from the sexual trauma and you're suicidal tendencies. Best to see a therapist to help you overcome your condition and get better. Only then you will be ready to help other people again.