Why am I so weird? People ignore me?

I always say the wrong things. I fumble and stutter with my words, which doesn't give off the impression I'm even mildly intelligent. For the past five years, I've been known as the dumb one... And I don't know why. When I'm messaging online (especially in group conversations) I see everyone has read my message... But they don't reply until hours later talking about someone or something different. I'm not interesting... I don't play a sport... I haven't found my niche/forte.... I'm fourteen and I just feel so alienated. I have anxiety problems and sweat over the smallest details. Why? Why do people ignore me... I'm not known for anything. I feel pathetic. Where is my best friend? Do I even have friends...the group I hang out with, they are passive about disliking me (so I just do them a favour and distance myself, it's for the better and I've tried before). Is this normal geez I'm sweating over this again >.< sorry this was long...