Oh love, you don't owe anyone an explanation; but you are totally allowed to vent here and talk about your experiences and thoughts and everything without apology. This is beyond sad, but it was out of your control and there is no fault in talking about it
I've been through this, in 2012. I blogged about it here, the day it happened, and it really helped me to vent. (If it helps you to know other people have experienced what you're experiencing, this is it.) The year following his death was so hard for me, and honestly life itself is just hard once there's a void waiting to be filled by someone who chose to leave. But things get easier. Easier to talk about, easier to set aside while to focus on other things. I guess I'm rambling because I know "I'm sorry" doesn't make things better and I wish someone had said something other than "I'm sorry" when it was me. I am always here if you need anything, even if you want to talk about this or your own mental health or just random thoughts throughout your day. Dang I wish I could hug you, but since I cant