My friend wont leave me alone

Ok... So I have this friend and I like her shes fun to br with but she ius constantly bugging me. When I get hom from school as soon as I walk in the door the phone rings and its her... And she calls like 5 times a day and she keeps on txting me she says ooo you are by best friend she wants me to go everywhere with her. Honestly I dont have time to talk or spend time with my other friends she takin up all of my time. And she dosent have many friends but I do. I dont want to hurt her but I need a break fron her what do I do?!?!?!?!?!?help

ok, I have a friend that is just like that. she will even ask if she can babysit with me! I swear sometimes she is stalking me. and then she copies what I say. so I got sick of her and I yelled at her and told her to leave me alone... but the next day she was all bff on me and hugging me... so I just making up exuses to not hang out with her and that worked for me...

I have a friend like that too, and he's really sensitive so I haven't found a good way to be like "I need some space once and a while dude" without hurting his feelings.
If you find a real good solution to this problem let me know.