I am very sorry for your loss, losing loved ones is awful, especially when it's a good parent. Everything will get better, I am sure of it<3 Try to do stuff that makes ya happy, music, writing, art, stuff like that helps me. (PLEASE also use h e a l t h y coping mechanisms, no self harm or anything like that, it's a horrible habit to start)
My father was killed when I was 11, I am now 13, it's going to be two years since he was murdered in April. It's hard, I think about it a lot, especially with things that happened close to his death, but I will be okay, eventually. It will get better. Trust me. Life is going to give us hardships, some will be worse than others, but we just have to do our best to fight through it. I hope things get better soon for you. I know it hurts to lose people. (I have lost a couple people because the wrong person had a gun, it's never good, and I have lost others for different reasons)