Best friend for life or not?

So I am a senior in high school and I am going to be leave to go off to college. We have been thinking about going to colleges in the same area so we can still hang out and see each other. We have been friends since the 3rd grade and became best friends in the 7th grade. We are really close but lately she has changed and she has been igniting an anger in me that I can calm down one second then have her fuel the fire again. This happens all the time and sometimes I can't stand to be around her. She is one of the rudest people I know but I also know that she doesn't think twice about what she is saying or doing. She doesn't know she is being rude, and when i bring it up later, once I have cooled down, she brushes it off saying that I know her and I should know that she doesn't mean it that way but it just is like that. That is always her excuse and she finds it a good reason for me to not take offense to the rude behavior. I have a lot of friends but she is my best friend who I have introduced to my other friends who have become her friends. I don't like fighting and I rarely do it, because when I fight I find a solution that ends the problem right then and there. That solution would be to end our friendship, but I don't know if that is what I want. One minute I can tell her everything and love her for keeping my secrets and helping me with problems only a best friend can help with. Then the next minute I am upset because she is being rude and selfish, and not wanting to be around her at all. I have another really close friend and I am her best friend and I like having two best friends. She is nothing like my other best friend. She is caring and never selfish, we have a lot more in common than I have with my other best friend. My other best friend get jealous of her. I have had trouble in the past with them fighting over me and I fixed it by being friends with both of them but telling my mest friend that shhe is my only best friend and that the other friend is just a close friend. Now I feel that I have 2 best friends and I really like it that way. I feel that this new best friend is becoming my best best friend over my old best friend because we have so much in commen but I still want my other best friend because we have been friend for so long. I am so confused and I don't want to hurt anyone. Should I continue to remain best friends with both of them or should I choose? Should I stay friends with my rude best friend or move on to my unselfish friend? How do I go about solving this issue without telling them how I feel about this whole thing and end up hurting one of them? Any advice?