Damn i am in trouble

In short i have obtained someones yahoo email password, and deleted the emails in their inbox, then i sent some emails from it saying some wrong things, and then i used his pasword to enter into his website as admin rights and deleted everything in there, and left a message on the homepage that was detrimental to him.

why? I hear you guys asking, because the same guy raped my sister about 4 years ago, now what disturbs me is that i initially started out in this as an ignorant little bot, just trying to stand up fo rmy sister, I stupidly used my own laptop at home and they have got my IP address and announced that they know my location, they openly stated my country and city, (i can locate a country but i didnt realise it was so easy to locate a city as well)

The guy is not aware it is me and he is saying they will find me from the ip provider and take me to court, my mum is going to kill me! I am now using a software to disguise my IP, but i think i am too late, at first i thought i could just say it wasnt me, as they didnt see me online, i never put my name there, man i am afraid so much that i dont sleep or eat, my mum is starting to ask questions, can anyone please advise me what to do.