Getting it out of me

so my husband moved out about two weeks ago, we're getting a divorce.  all was good for a while, i felt confident I had made the right decision.  Then I plumetted into a major depression.  i just keep going lower and lower.  i can't deal with work, home, school, kids...  i've been suicidal before but still been able to take care of my shit, this time I've missed work, fell three weeks behind in school, and can't handle anything in life it feels.  everything continually gets worse and it just feels like it's my fault.  a friend asked if i got back together with my husband if my depression would go away, at this point i don't know.  i was down with him but this is crazy.  no matter what choice i make i'm hurting someone or letting someone down.  i cut also.  about a week ago.  it wasn't deep and just on my leg but it opened a gate and now that's all i want to do.  everytime i get overwhelmed or upset or angry i just want to cut.  i'm so stupid for doing that.  bad decisions left and right.