I can't make friends in a new country

Hi, my name is Zach and I am 15. I moved to Germany a maybe year ago. When I moved here it was like August so school was coming. When I got to school, I tried to make friends but nobody wanted to be friends with me. I am very quiet person, like when somebody asks me something I sometimes refuse to answer, I don't know what is happening to me. I am not leaving the house but that's only because I have problems and I don't want to go anywhere. I am always chatting to my friends on the internet so I am always on a computer or on a phone... The main problem is that I can't make friends, and I am a very quiet person... I don't know how to fix that so do you have any suggestions? Thank you, Zach