IMO- Not in middle school. You're still a kid. Lolita gives the image that you are younger, but there is sometimes some sexual vibes given off of Lolita. But I wouldn't say no to a Halloween Lolita at the moment.
You should wait until high school where you can go to school wearing whatever you want without anybody really caring to become a Lolita regular. I dress up in crazy outfits when I'm bored, and nobody really cares. It doesn't matter because everybody has
achieved their sense of style by then, and you just see that person
dressed according to their personality.
Don't worry about people's opinions at the moment. You can dress Lolita now, but you can definitely show you are better than the people making fun of you by ignoring their snide remarks.
You gotta be confident in your style!
You'll feel much better wearing Lolita if you're confident.