I think you should take it slowly. Don't go on sleepovers immediately but go to your friend's house, stay over for a few hours, go home, and do it again and again and let the hours increase. I think you shouldn't sleep over just yet. Try to overcome this homesick problem first. Also, to stop thinking about your family and home, try having fun! Overcome your thoughts of being homesick with other fun thoughts. Have fun with your friends and forget about your home, but not in a bad way. Just temporarily so you can have some fun in your life!