I am so sorry for your loss. It makes perfect sense to me, that you are having a terrible time with it!
When my son was a junior in high school, his best friend shot himself. It was a very hard time for all of us. His friend was supposed to be the best man in his brother's wedding the week after his suicide and my DS was asked to step in - which he did. They had a funeral on Wednesday and a wedding on Saturday. I am telling you all this because the severity didn't hit DS until quite a while after everything settled down. I still start crying every time I hear the boy's favorite song or see a picture of him ao talk about him (it was 4 years ago). He was here so much ... he could have been mine.