Dear xx
You said you didn't have any friend in the high school.don't worry ,you just need some try.
maybe you can talk more with you classmates.and make you look friendly.try to be more outgoing,then the others will like you.helping others is also a great way.they will think you are a good friend.
high school is a important part of our development.in some ways,it's different from middle school.although it'very diffcult,you shuold adaptation it.
try your best,i'm sure you will get over it!