You can't tell me I'm wrong

period is placed at the end of the sentence, not after the first word.

Iceu. Is his username

ok

I couldn't remove the . for some reason
I go by Iceu

Sometimes if you try to remove the dot it doesn't recognize it as a new username

That's what his username is

well you dont need to put it
we all know who you mean when you just say "iceu"