Husband asked me for a divorce

Me and my husband have been together since high school and have 3 kids together. 5 months ago we lost our oldest daughter. She was 15 and was run over on her bike by a drunk driver. Our world crumbled. We are both severely depressed. We went to a grief counselor. Me and my husband have been fighting more than ever. We say I hate you. He calls me a bitch. I call him a POS. He's called me a shit mom, I've called him a shit dad. Our marriage went so far down hill. We were never like this. He served me divorce papers today and I was completely blindsided we started screaming at each other and he said he can't do this anymore. I threw something. Not at him. At the wall and he did the same and then my 10 year old son was downstairs looking at us and I started crying. My husband took him back to bed and packed his stuff and left. When our daughter died she took a piece of us with her. A piece of our marriage. Our family is broken and now it's about to be physically broken. My kids are already struggling and now I have to tell them me and their dad are divorcing. My husband said we can just talk through lawyers because he doesn't want to talk anymore. I broke a family picture that was from less than a year ago. How tf could we be a normal happy family a year ago and now we are broken.