What can be done about trolls? They have been around since the dawn of Internet forums. If name changing is banned, people will simply open new accounts and do it that way. That is exactly what they do on the other forums I use.
These kinds of attention-seeking people are born everyday, they only thrive if they have an audience, and they only have an audience when people hang onto every word that they're saying, and over invest to the point where they end up being hurt when the truth is revealed.
You have to, by default take most of what you read with a pinch of salt. You have to by default, protect yourself, especially when you are revealing a vulnerable side of yourself online. Just like you would not stop a stranger in the street and divulge your inner most thoughts and troubles to them, or invite them into your home to discuss their own problems. If you choose to take things further, you do so at your own risk not knowing what that person's real intentions are. You don't know who is behind the username, that knowledge is all you need.