Lost my dad and can’t cope with guilt

I lost my dad on Monday. He was sick and at home for a month. He had chronic heart failure. Prior to this, there were multiple times when he stayed at home for a while, got his treatment and got better again. But this time things were different and his situation was not well. During that time I was working hard at work. I was at work from the morning and came back home at night because i was working on a tough project.. I could not give any attention to my dad.i came home to sleep. I could not understand the severity of his situation, I firmly believed that he will be alright and he will get better again. I could not even imagine he would die. I dont know what happened to me and Why I acted like everything will be okay and he will be okay.. i wish i could spent more time with him on weekends, text him more when I was at work. I wish I was a better daughter.

for the last 1.5-2 years, our relationship was complicated... we were closer when I was studying abroad.. i wish things would have been different. I dont know how to cope with it.
he died in front of my eyes. Me and my mom were at home. I was shocked and started crying and I was numb. I could not even hold his hand for the last time

i dont know how should I continue to live. I do not think i will ever get over this.