Why does she hate me?

im 15 and i gave out my grandma's phone number to my friend. my friend kept calling my grandma and asking her to take her out to eat. i was mad at my friend. she called my grandma three times. i heard my grandma yelling to my friend "dont call here anymore. stop calling me. have alyssa call me!" to my friend. im mad at grandma for being so mean to my friend. i talked to grandma. she said "im never going to pick you up again, do you hear me?!" she was yelling and i hung up. she called me the next day, she said sorry because she was crabby. i said sorry too. she said she cares about me and that we have fun times together. she said she wasnt mad at me. she said she loved me and i said love you too. then i hung up. today, she picked me up. we went to the store together. she was puting her arm around me and calling me honey and sweets. she usually does this to me. is she still mad? help! i feel so bad. why is she acting all normal again?