Any good advice on how to get over my dad's death?

He passed on the 21st september 2009, it was very sudden because he had lung cancer and didn't tell us, we only found out a week before he died, he passed away at home with all his kids at his bed side, it was the worst thing that I had to go through because I was always neglected at home by my mom and siblings, my dad was the only one that cared and stood up for me, I know its impossible to get over it but since I had my first baby last year december I cry and miss him more often because no one not even my mom visits my baby she lives just 10 minutes away, I just wish my dad was here because I know without a doubt he would be here everyday, it hurts even more because he was still alive to see and play with all my siblings kids and his not here to play with my son, I'm just so depressed and feel like he just passed away, what can I do? I cry almost every hour