I'm 4 ft 6 and 18 years old?

I'm 4 ft 6 18 years old I'm tired of people treating me like I'm a kid. I was walking today on a beach and this girl volleyball team was jogging by and they all were like 2 ft taller than me and looked at me and laughed at me. People to me r like giants and it's especially hard making guy friends because they r all bigger than me. I can't stand it. Eberyone is larger and no one understands. Girls constanyly laugh at me and I can't say anything cause their bigger and their boyfriends could beat my up. I'm going into my senior year and I'm going to be the smallest kid in school I cant stand it and I need some advice pleasssee