I am going into 7th grade, junior high, and I've been in elementary school since kindergarten. How do I get over the feeling like everything is changing?

Don't think of it as "all or nothing!" A lot of the same friends and acquaintances will be going to the junior high. You aren't moving to a different state, just a different school building, and probably one that is bigger. You will definitely have a lot of new students as well, but remember that EVERYONE will be new. Remember that when you went from 4th to 5th grade some things also changed then. You are probably more ready for this change than you think. Try to focus on the new adventures and opportunities instead of only the unknown. Good luck!!