There is one secret rule which always works to combat homesickness. If you follow this rule your homesickness is guaranteed to disappear almost completely. Here it is:
Rule #1: Do not be alone. Loneliness fuels homesickness. Most of the time when homesickness hits it's when you are alone. You catch yourself thinking about your family and your friends. Next thing you know, you miss your mom and your dad and your best friend. When you're all by yourself in a new and unfamiliar place, homesickness is likely to occur, but that's okay. Go talk to someone. Anyone. You don't have to be their best friend. It can even be someone you've just met or even a stranger. Go up and introduce yourself. Ask them something as simple as the weather. Or go out on a limb and let them know how you're feeling. They might have their own insights into how to help. Having a conversation with a real human being (not a message to your friends on facebook) will make you feel so much better.
Rule #2: Say yes. This rule is taken from improv. However, it has been proven to help combat homesickness and even avoid it in the first place. When you are separated from your home and your friends, you will sometimes feel like doing nothing. You'll want to stay inside (usually alone) and never leave the house. Or worse check up on your friends via social media. (See Rule #3.) The trick is to say yes to everything. Someone asks you to go for a walk with them? Say yes. Maybe an acquaintance asked you to try out a new restaurant with them. Say yes. Your new friend wants company doing something routine like grocery shopping? Say yes. It might not sound like "your thing." Or it might even sound like the most boring activity on the planet. Just go with them. It'll take your mind off of being homesick and you'll get to do something out of the house. It will make you feel better. I guarantee it.
Rule #3: Stay away from social media. Don't worry about the people at home. You'll want to look at facebook and instagram see if all of your friends and family are having fun without you. Feeling like you are missing out just makes homesickness that much worse. Cheesy as it sounds, if those people are really your friends it will be as if nothing has changed and no time has passed the next time you see them. If you must go on social media, post some cool pictures of the new activities you're doing and new friends you're making and then log off. Remind yourself that everyone on social media is presenting their happiest-looking selves, not necessarily their genuine selves. Everyone has good days and bad days and no one is happy all the time.
Rule #4: Be patient. This feeling will pass. It may take awhile, but it will pass. If you can't talk to anyone, find something fun to do on your own. Maybe that's taking a walk or writing in a journal. Just remember that homesickness is normal and everyone else goes through the same thing.
Homesickness is not really about missing home.  Instead, it's about feeling comfortable and in a way, it's an after-effect of stepping outside of your comfort zone. Your routine changes, your atmosphere is different, and your new "normal" has morphed into something that feels anything but normal. Just try to remember why it is that you decided to leave home. Maybe you have just moved to a new city to start the next chapter of your life or maybe it's just a month or two abroad. But for whatever reason, you thought it would make your life better. Big changes do take some adjusting and you need to be patient with yourself. Before you know it, you'll be saying goodbye to your camp friends or school friends. In the meantime, you don't have time to be homesick because you're too busy soaking up the amazing moments you're having away from home.