TeenHelp - Anxiety? Need help!

Hi, i'm 13 years old and i live in Denmark even though i come from iceland. This is my story. So when i was 7 i moved from Iceland to denmark, i didn't know how to speak danish at the time so it was new to me. At the beginning i didn't talk at school as i still had to get used to the new school and the language. My parents thought it was completely normal but as months got by, i still didn't talk. I didn't talk at school for 3 years and my parents started getting worried. They often asked me why but i didn't reply as i didn't know it myself. They had done almost everything, i tought many of those things were really unfair and it was none of their buissenes. They forced me to stand infront of 30 people and talk about my dog and my new shoes. One teacher also took me out of class everyday and we sat alone him trying to talk to me and i had to do some excercises. I often cried myself to sleep because of that. Then after those 3 years i got really great friends with Jo. ( we are gonna call her that ) Jo hadn't been doing well either as she had/has anger issues. I started being more comfortable when she was around and i started talking. We were just us and no one else. We got bullied a lot because of her anger issues and my quietness but i still felt better as i had a friend and finally had the courage to at least say a few words. 2 years later a new girl started in our class and we became like a trio. Everything was going great until a few months ago. They both had to move school. I was really sad as it was kind of jo who kept me alive. I still she Jo almost everyday and we go rollerskating with our dogs. It's really hard at school, i am really tired, not able to concentrate and i don't have friends as everyone walks away from me when i come and ask what they are doing. Many teachers have asked if i'm okay and i just say i'm fine, just a little tired. Not long ago we were on a school trip with my english teacher. ( my fav teacher ) I was walking alone and he came up to me and asked what was going on. I told him nothing and asked why. He said he saw me this morning were we had to read and he noticed i wasn't realle concentrating wich is unusal of me. It was one of my bad weeks were i had been worrying a lot and crying myself to sleep everynight. I felt so sick and i just couldn't look in the book. It was hard to breathe. I regret saying i was just tired as i think he is the only teacher who might understand and see what i'm going through. I still cry myself to sleep atleast 3 times a week. I'm scared of going to sleepovers as i can't control my crying. I don't know what to do and i've been looking at it online for some time as looks like i have anxiety. I really want help as i'm so empty and tired of feeling this way, i just can't get myself to tell anyone. My parents would never understand they just get mad if i cry for no reason and think i want attention. No i'm not having suicidal thoughts or anything but i often think how it would be if i wasn't here, if i killed myself, if anyone would miss me. I just don't really see a point of living. I mean do we just live to die? What purpose do we have? What purpose do i have? What i really find helping is animals, they really calm me down and at night my dog actually often prevents me from crying. If it's bad i will be rolling around in my bed and crying and not really being myself. I will only realize what's happening when i stop crying. On really bad nights i will have the same "nightmare" over and over. It's kind of a nightmare kind of reality as i will wake up sweating, not remembering anything, being totally out of my freaking mind and i feel like there are these balls in my room that are suffocating me and i can't breathe. I will scream and cry and my dad will come in and hug me until it's over but he never assumes anything is wrong. Normally i just find it really hard to breathe and my heart will go crazy so it hurts in my chest. Someone please help me, i don't know what to do. I know it's long but i really felt the need to finally tell someone who hopefully wont judge me. I'm just tired of hiding under that smiling mask. Thank you.