I feel im in love with my best friend who is going out with my cousin! what do i do? i need her..?

im in love with this girl who is one of my best friends, ive known her since the 6th grade and i keep having dreams of her and it just happends i cant controll it. me and her are in the 9th grade now and i still feel these feelings for her, ive always been their for her and i always talk to her, me and her have talked about a situation we had about people at school telling her i like her which i do but i keep telling her i don't and she believes me but i know shes getting the idea year after year. shes been going out with i guess i can say my 2nd cousin and i mean i like him because hes always their for her which makes me happy of course but i feel he can do so much more.. ive gone out with allot of girls and i know how to work this but IDK i feel like crap like i need her. do these dreams i have of her ALL the time mean something? i need help badly because its been 8 months thy have been going out now and 4 years that ive been trying to be with her. can someone help me i need facts and opinions please.......