I cried as I read your post, as you could have been speaking my own thoughts. 2 years, 3 months, 4 days after my mother's death, and it still hits me like a punch in the stomach when I wake up. My mother had all the answers, like yours, and I know I am soo soooo lucky to have had her in my life, but it just isn't enough, is it? The world is so empty now.
The only advice I can give is this: talk to people who love your mother as much as you do, cry with them, just so you know you're not alone in your terrible grief. Nothing can make up for the loss of your best friend - but being around people who don't understand can make it so much worse. I have a mini-shrine on my desk with pictures of my mother and some of her personal belongings, and my husband thinks it's "unhealthy." I don't share my feelings with him because he has no clue - both his parents are alive and one day he will know what comfort a shrine or any remembrance can bring, even though it brings me pain, too. In short: do whatever you need to do to feel better, and don't let anyone tell you to move on, get over it, etc. Do it in your own time, your own way. One day it won't hurt as much -- it'll still hurt, but it won't take your breath away and squeeze your heart like a wet dishrag.
Sorry such a long post -- I really feel for you and your pain. I hope you find a way to alleviate it somehow, even for a little while.