I can’t really talk you through this by BL posting - but if you feel up to it check out the Stages of Grief. It seems that most people go through a number of similar stages (though they all experience them very personally and individually). Denial or disbelief as you describe is usually the first reaction. Anger, as you describe Aldo, is also very common as an early stage and usually comes next.
The good news is that the process is natural and eventually everybody moves through the stages and comes to terms with their grief/loss and can move on at peace with themselves while still treasuring and respecting the life and memory of the person they have lost. The best thing is usually to understand your reactions are totally understandable and normal, then talk it all out with people you trust and not bottle it up if you can avoid it.
Here’s a link to something that might help you see what you are experiencing is pretty universal and consistent:
https://www.healthline.com/health/stages-of-grief
Sorry if you already know this shit. I don’t know what else to say.