It's like HollowOfHaze said: Don't obsess about people.
And the endless cycle does indeed not help but it starts with you. Only you can stop it.
The thing is, it's hard to have no friends or people to talk to, and I understand the situation. I think a lot of people do.
But you need to understand that friendships need time to grow and develop, especially when growing up. As a small kid friends seem to be made instantly, whereas it's much harder and takes more patience and effort when you get older.
Do you cling quickly to someone when you have contact with each other? What happens exactly that goes wrong?
See, people need space. Some people more than others. Sometimes people need time to open up, some people want a logn-lasting friendship and would want to get to know someone but in a steady pace.
Maybe there are hobbies or other interests for you to do and spend time with people who have a similar interest in real life. Focus on that hobby/interest, talk about it. And when it's time for people to head back home and you've enjoyed yourself, go there again (next week or whatever) a couple of times.
Then when there has been some sort of connection established, why don't you try to stay in touch with each other and meet up once a week or once every two weeks? (Depending on both of your time schedules.)
Stay in touch with them and be sure to communicate with them. So not only telling them what you want to do, but also asking them what they want to do, how they are feeling, etc.
