Unfortunately, there is no way to change your in-game username. The only username that you can change is your forum one. But I think I may have a trick you can use to log into the game with your current username.
First, open up the feral heart game and type in your username regularly without the symbol that you can't type. Then press the check box next to it so the game remembers your username.
Then go onto google or some search engine and search for the squiggle symbol. I'm assuming by squiggle you mean the tilda, which looks like this ---> ~ If that's the right symbol I want you to select it with your mouse and then copy it.
Next, go into your feral-heart game folder. If you scroll down, there's a lot of files that end in .CFG. But if you scroll all the way to the bottom, there's one named "settings". If you can, open that file with notepad so that you can type in it.
At the bottom of the file, it should say:
[Login]
username=
And after the =, it should have the username you typed into the box in game. Paste the squiggle into your username where ever it belongs, save the file, and restart Feral Heart. The symbol should be in your username the next time you start it up.
Then when you need to log into the website to play, do the same thing where you copy and paste the symbol into the username space.
I hope this helps! If you need me to go into more detail or provide you with images I can, it can be a little confusing.
