How to deal with the grief of my Grandma's Death?

I am 15 years old and ever since I was little I always had my grandma there for me to call and talk to with every night. I stayed with her every other weekend, we called each other every night, we saw each other every Wednesday and plus many other days. She was one of my best friends and I have had a really ruff time since the Summer on June 29 2011 she passed away and she was fine the night before when we left and we thought she would be fine and we were going up early the next day but she passed away during the night on our way up there. I only have one regret and that would've been for me to stay with her. That was the worst day of my life and me and my mom have had a really rough time dealing with it because we were all best friends. It has almost been 7 months and I miss her so much I actually cry more now then I did its like it has finally kicked in but I still can't believe it because it was unexpected. I don't know how to deal with this sometimes I break down and cry at school and I cry myself to sleep 2 to 3 times a week. Since she passed away I have been diagnosed with Fibromyalgia and I am always tired. My doctor is sending me to a counseling thing because she said kids with fibro usually get depressed. But its not that I have fibro I miss my grandma unbelievably much. I talk to my mom sometimes but I try not to because I don't ant to make her sadder then she already is about it. I talk to my boyfriend and he always helps and comforts me but I still cry and cry. I don't know what to do to help myself not cry as much about it I try to remember the good times and I do smile but I always seem to break down because I miss her so much!! Any suggestions? Thanks! God Bless<3