no me interesa que me envies mensajes ...preocupate por tus amigos y dejame tranquila
"...I don't want that you send me messages... Worry about your friends and leave me in peace."
That would read better in English:
"...I'm not interested in your messages...look after your friends and leave me alone".
"preocúpate" is a way to say "take care" "look after" and does not have the sense of "worry"
Also "leave me alone" is the most used expression meaning: "Déjame tranquila" o "Déjame en paz"