What should i do now?

i did big mistake of in my life, i explode my cousin sis's all number in chat-room, and sent bad pic in her mail, because of she avoid me many time in chat and phone, whenever we fight she ignore problem and never try to solve it, i am poor guy either than my sis, my relation about 3 years, i got in jail for 3 days and got punishment by police, and now she left and said never talk with me.. :(( i got angry and i did mistake, please friends now what should i do for get back my sister..... i really love my sis in deep of my heart, i felling guilty, plzzzzzzzz suggest me...:((