I can relate to what you are going through to a point. I am in the process of watching my mother die. I am 34 years old and I lost my father at the age of 28. He passed in his sleep quickly from a heart attack. He was my son's "father figure" he meant the world to me. I was the typicle "Daddy's girl".
When my mother was dx with cancer in Feb of 2006 I thought no big deal we will beat this like we beat her uterine cancer 8 years ago. Well reality is here and I am watching my mother, my best friend die in front of me every day. I moved her into my house with me and my son and I take care of her house and mine while supporting her and my son. It has been the hardest year of my life but also the most rewarding. I was able to take care of my mother for the first time instead of her always taking care of me. Be thankful that you had the time to take care of her and to give back to her a little of what she gave to you. I regret not being able to say Goodbye to my dad, but I know that when the time is here I can say Goodbye to my mom and tell her everything that is in my heart. I have already started to do that. I know it will take alot of time to find comfort. I still have flash backs of finding my dad, and I tend to get panic attacks. It does get better. You never forget you just learn to cope.
I hope you find the comfort you need, but dont rush it. You need the time to grieve. I tried to not let myself cry and grieve, but all it does is makes it worse.
Take Care and keep me updated on how you do.