I am so sorry that you received such a troubling letter from this unknown person. I'm sure it is very upsetting to you, and even more so that your father would disclose your address to someone unknown to you. Please remember that this man is behind bars and cannot hurt you in anyway right now, and no matter what your father may or may not have told this person, is not a reflection of who you are right here, right now.
Take some deep breaths and put the letter up (or throw it away) so it is not a constant reminder to you. I know this is extremely difficult, but try to focus on your surroundings right now, and get back to what it is that you were enjoying so much about today. Focus on the good here and now, and let go of the negative feelings regarding that letter. No one should ever have the power to turn your day into something bad, especially someone you've not met.
I am so sorry and you have every right to be upset as your Father gave your address to a stranger and for what reason? So this inmate would have a pen pal.........bahhhh.
I am glad you threw the letter away and at this point I am not even sure I woud open anymore mail from my father if he did that. If your father is sending you mail for the rest of the family then I would tell him to send the mail to the right address as he has broken your trust.
Go ahead and vent and get the anger out and then let it go. If any other mail comes write return to sender on it and throw it back in a mail box.
Hugs to you sweetie.
I'm very sorry that you are being put through this uneeded stress, and I agree with everyone on here, because it sounds just ridiculous. I can not believe any parent would try to set up correspondence with somebody they were "friends" with within the prison system. I feel so bad for you and I know from personal experience that you can have these letters stopped if you file a complaint like advised by other members. Please take care of yourself and know you have a very supportive and loving family here my friend.
The best of luck to you. I hope this situation can be straightened out immediately.
Your Bro Sam