I dnt want to put her through it anymore?

i have been a self harmer now for 3 years and am now on anti depressents. i try everything to change and make myslef happy but somehow i always go back. i have a fab older sister who knows about everything but i feel im upsettin her too much and hate it. i dnt want her to worry about me. im issues with food now too but i think its coz of the pills. i hardly eat anything and this is hard to keep secret and my weight is decreasin quite a bit. coz shde knows but my self harming its hard to hide from her and wen we go shopin and stuf we have always shared a cubical in the fitin room and when i dnt want to she knows ive been self harming. ive tried everything to stop and i feel disgusting. i wish i never told her in the first place because i love her too much and im hurtin her. what shud i do?