What do you do when you keep getting looked down at?

I have 2 ''perfect'' sisters that my parents praise most of the time, the one is 21 nd the othe 24.. im 16 and i am 16,,, so u can imagine how i feel.. the yougest of three,,, (the worst), they torcher me,, and ever since i was youger they were always better than me in everything, and my parents would always look up to them, when i do somthing they would always match it or do better, i feel so smal compare to them... and come on im 6'1,,,, how can i feel short compare to them.. my parents dont see it and i yess ive tryd tawking to them but they think im over reacting, but they dont put themselves in my shoes,, ill tell u how bad it is... i broke my ankle in a rugby match bout 2 months ago, and i had to find a lift home coz my sister had an interview for a modeling in Durban??? plz tell me how is that fair? i need to know what to do to end this torcher,,, i just wana be appreciated for being myself and not fake being like them..