((Tinkerbell)) - I'm so sorry you're in over whelming pain. I think you may need some in-patient time to get stable. Do you have a therapist to talk to? You're dealing with your pain but also the grieving. I've heard many times some depression can be anger turned inward and I think self injury is anger. I think it would help to get in touch with this anger in a controlled way...with a therpist.
When I was in the midst of my marriage problem......getting contructively angry actually saved me. I had 2 choices - to let them destroy me or survive and get a little mad. I know some who are suicidal want the pain to end and that's why they want to die. You mom lived her life but you're not done yet.
Abuse victims usually have a hard time finding their inner strength. Right now you're in the narrow tunnel and can only see one way out....but death isn't the solution. You have things to do and you must go on with your life. I want you to find some peace.

Sorry if I've analyzed this too much but I've learned a lot from the bad things I've gone through. I don't know if this would help - can you put all this aside and take it one day at a time. Imagine putting all your pain in a locked box and only let it out when you see your therapist. Deal with life moment by moment - not the past or the future.