What are signs of social or normal anxiety? Do you think I have it?

I wanted to know if this was a normal thing or if everyone experiences it. This is long, be warned.
When I get REALLY nervous about something, I get sweaty and shaky and my voice is kind of shaky as well. This had happened once last week, when I was nervous about something at school. I got sweaty and my teeth were chattering and I was visibly slightly shaking. I constantly feel like something bad is going to happen. For example, I get in a car. My thoughts are: Oh my god I'm going to crash and get seriously injured. What if i die??
I hate talking to new people, it makes me feel like I can't say anything wrong, I have to act perfectly and if I make a mistake everyone will laugh at me. Heck, I even feel like this around my friends. I always feel like I have to look perfect because everyone will judge me. I'm currently being teased at school over a boy I don't even know saying he's my boyfriend. He hugs me and thinks I'm his gf. Every time someone says the word boyfriend or "There's your boyfriend!" I get like a sudden rush of panic and fear. I'm worrying about something almost the whole day. At night when o try and sleep I beat myself up over things that have happened years ago and I can't sleep. Like I turn red and think "I'm so stupid! Why did I do that?!" And stuff like that. I feel like I can't even talk to my parents because I'm afraid of being judged and it's too awkward for me and I feel like everyone will think I'm weird and overexxageratung and stuff. I always feel like no one really likes me and I'm just being a bother. I feel like I don't belong. The only person I could ever talk to I think would be my BFF who I rarely talk to anymore, Michelle. I don't say what I think because I'm too nervous and I'd sound shaky and people would think I'm stupid and whatever. 
My brother has anxiety. If I told my parents I think I have anxiety they wouldn't believe me and they'd probably look at me like, "No you don't. Your brother has it, that doesn't mean you do."or something like that. They never beleive me over things like that. Things make me so nervous I could cry, but I dontbecause again, I think I would be judged. Help? Do you guys think this is anxiety or worry? I'm in middle school by the way. Kinda young, but I need help. Thanks!