Anyone have any suggestions to help deal with an 18 year old and a 17 year old daughter.?

My 18 year old daughter is preparing to go to college. She is mature in some ways but not in others. Right now, I am starting to show signs of the empty nest syndrome, and I really want to be a big part of her graduating high school, and to help her with her transition of leaving home and going to college, but she is doing everything to keep me completely out of her business. Every time I try to get involved, she gets angry and heads over to her grandparents. She has taken all of her college mail, graduation announcements, cap and gown, etc. to her grandparents so they can help her, but she won't even let me look at it. It hurts my feelings. My 17 year sympathizes, but she stays gone most of the time. She says we are growing up, mom, you are just gonna have to accept it. I think most of these attitudes are influenced by money. The grandparents have much more money than I have, and my 18 year old thinks that if she includes them more that they will be able to fund things I will not be able to. And my 17 year old has been hanging out with this family that seems to have unlimited amount of funds, and shares it freely with her. I know I should feel grateful that they have financial help, but why do I feel like such a loser, and why do they have to exclude me. I have always been there, and I did raise them this far.