-Gets rocks ready for throwing-
Nah just kidding. You're not the first person to bring this up and you won't be the last. I've seen a few of these "Maizy" characters before. I've seen characters that have similar names that are spelled many different ways. You would think that you had come up with a really unique name for your character, but in reality there's probably millions of others with a similar name.
You're right, you are over-reacting. It's really nothing to fuss about. The only time you can fuss about it is when someone completely copies your character; name, appreance, bio, and so on..