So, I was hoping to change my username, but after filling in my new username and password, it says that my password did not match. I've tried this several times each day since last week.

Try changing your password and trying again, that should solve this problem. I don't know why it happens, but I've seen it fix the problem for people before.

: Thank you so much for your help! I managed to change my username c:

Ohh congrats :D That's my favourite fish. X)