This issues has been addressed in the past, here is a quote I found by Bawfle on how to deal with this issue you're having with resetting your password.
If you aren't already, I suggest resetting your password at the Homepage through 'Forgotten Password'. Though, if you are still having problems (or this is what you did in the first place), then I suggest addressing the matter to an active Member of Staff (https://feral-heart.com/index.php?option=com_content&view=article&id=28&Itemid=52) who can give an accurate answer or solution to this specific problem.
I hope this helps somehow!
So you changed your e-mail on another account you have, as well as the username, and changed it to onesidedloves? And this is because you had been using 'automatic login' on the login page and forum for the other account, so you forgot the password, and you already had forgotten the e-mail you were using for that account?
Only thing I can suggest is contacting a member of staff to see if they can get hold of the e-mail you are using on the account you are trying to change your details on, since you cannot remember the e-mail you used.