I changed my username without my password.

Good afternoon, 

So I went to https://www.minecraft.net/en-us/profile and I tried to change my username to fffrfef , a random username . I added "12" as my password. I right-clicked this button: https://prnt.sc/v9lku8 and then edited this piece in the inspect menu: https://prnt.sc/v9llxz and changed "false" to "true". My password is a 19-character string but my username changed with "12". I was testing with this random names and I didn't mean to change it to fffrfef. I am requesting a reset to my previous username If that's possible.

Thanks in advance.