From the words of one of the greatest rappers, Guru (

),
"Don't even feel like drinking, or even getting high,
Cause all that's gonna do really, is accelerate,
the anxieties that I wish I could alleviate."
Think about it. Turning to substances will not help you in the long run. If you get stoned, you might actually start thinking about the loss more. Being high makes you think in a different way, and under your circumstances, it will expand your issues to a deeper level than you'd wish. Drinking isn't good, either. It will simply mask the issues and they will all crash land on you later. My advice for you is to face it. Let time do the healing. The death of a loved one is NEVER easy, and the feelings overtaking you are completely normal. As hard as it may seem, you have to face the realities of the situation and accept it. I've been through what you have, and it's difficult. If someone were to tell me what I'm telling you at the time of my loss's, I wouldn't have listened either. Simply because it isn't easy to let go. But try. If all else fails, simply give it time.