My daughter's mom just passed away and I am in shock

my kids mom just passed away. I am in disbelief, heartbroken and just totally in shock. My daughter now has to grow up without a mother and I feel so bad for her. It wasn't supposed to happen this way. My daughter is 5 and she knows mommy isn't here anymore. My heart hurts so bad for her. She was only 30 years old. A beautiful soul. Now grandma served me paperwork and is trying to take custody of my daughter because I had a prior substance abuse problem. Mind you I am clean and sober now. I am just so confused. I can only take so much..