Is this love normal?

I had a sister, who has since passed away, but even when she was here with me she was my everything. I don't feel like the love I have for her is a normal one but maybe it is. She was my best friend. She was my whole purpose for existing. Our relationship was not only sisterly but maternal. We loved to sing to each other. I would hold her in my lap and rock her. We were inseparable, often sleeping in the same bed. If I could live with her for the rest of my life even as an adult, I would have. Now that she's gone though, I feel like I will never be happy again. Even when good things happen I'm never truly happy because all I want is her back. When people try to get me to go to places I once enjoyed, all I can think about is that I'd rather go with her. I hate that I have to spend Xmas with those I've made plans with, when I'd rather spend it with her. She is forever on my mind and I feel like no matter what happens in life, I will never be happy. She is the only thing that could make me happy. It's really hard living without her. I wake up every morning and I'm disappointed that I woke up for another day. If I have nowhere to go I will sleep in till 1pm. My smiled are never genuine. I'm just so unhappy and everything feels meaningless. People say time heals all wounds, but she passed away 8 years ago and I am not ok. Is this love I have for her normal? I do not understand it.