Sorry dude :T
Hey yo I'm sorrry about your art being stolen it sucks that this person is stealing the stuff you worked hard on
Start putting your account name on your art that will stop the trolling, it's considered stealing if it has a name on it. More people will target the troll instead of you.
People can just erase the watermark though. It won't really do too much
There a troll with other accounts as well.....