problems with my grampa?

[Pestysheet577]

ever since i git a new iphone for my birthday on the 6th of april he has been so strict...he doesnt let me charge it in my room, he is always asking who texting me and who has been calling m and who im talking to, and what im doing...at first he said i could only have him and my grandmother on my contacts...why does he di this to me? i just want to be like any other teen, im 14 and i am not alowed anything like snapchat facebook skype instagram or ANYTHING they are killing the part in my life where i can make my own decisions and im a young lady and should be able to mature...and they are keeping me like im immature and they are making my life difficult... when kids at school ask if i have facebook its shame saying no...aswel for snapchat and instagram i feel left out....what can I do??
i know if i wa with my mum all this would be different and i would actually be able to leave the house with a tank top or something that doesnt have to cover my collar bone i feel like they are holding in my maturity..