My best friend passed away a few months back

My best friend and I were friends for years. We were friends since 4th grade and have been best friends from then. 
He was the guy I told everything. Everything from my smallest insecurity to everything that happens in my life, staying at each other's houses etc. Then, we got into college and went our separate ways but always stayed in touch. Whenever he came to my town we always had a meetup over drinks.

Then he got in a relationship in his college and everything went well for an year. But then for some reason, they broke up and he got kind of depressed. Then after a week, he committed suicide.

We are a group of 3 friends and that stupid idiot didn't call us even once. We only got to know what was going on when he did commit the deed.

Now I thought I had processed this grief, I had grown over it. But, when I drink, I again remember him. This happened at the times I had drunk quite a lot. I don't know how to get over this and I would like some advice for this