I feel like I have no friends. What can I do?

I feel like I have only 5-10 friends. And hang out with 1-4. I use to have alot at my old school but they all turned on me. But don't say there weren't my real friends. Don't tell me what I already know. But I feel like a loser. An outcast. How can I make more friends after summer is over? I'm going to 8th grade and I wouldn't mind having younger friends. Any suggestions?