Why must they treat me like this?

Im fourteen and the youngest im my family and the only girl I have three older brothers and a twin brother whos older by 18 minutes my older brothers are (16 19 20) my mom passed away when I was six so its just me my four brothers and my dad my twin treats me like his equal cause hes my best friend but to my other brothers and my dad im nothing more than a difenceless little baby I get that im still the only girl and the youngest so obviously they are protective but really its too far im always treated like I should still be in diapers im not aloud to date ever I typical rule for a dad but to the extream that if im caught even talking to a boy my brothers come over put their arm around me and say that im their baby sister and im 100% off limts and then theyll use some sort of threat also im never aloud out alone if I wanna go out with a friend fine but I cant go out alone I need to have either my dad or one of my brothers watch me and that includes even having my twin watch me im always treated like a little kid say I skin my knee im forced to lie down for the rest of the day and im not aloud to do anything and im taken care of all day like im incapable of doing anything but breath I hate being treated like im an infant while they treat my twin with all the freedom that I wish they gave me I sware that if one them thought of it I would be put back into diapers and be kept a baby forever I try talking to my dad and brothers but them just say that im their little baby sister or baby girl and they just want to protect me and also the very popular your just trying to grow up to fast my twin tries to help me by talking to them but they just block him out how can I get them to relize that im not a baby anymore and to start giving me some freedom