I get lonely in the summer. Is that normal?

I've noticed that every year, I feel less and less happy. I feel alone. Like nothing good ever happens. I feel as if I'm not living my life. I dont do anything fun, because to be honest I don't have many friends. They're busy most of the time, and we dont see each other much. I always notice that during the summer I get more lonely and sad. What could I do to make my summer better? Take into consideration that I am only 17 years old without a driver's license, do I can't drive myself around.