daggnix - A person who tries to be great but ends up being a total mes

A person who tries to be great but ends up being a total mess. They’re like a kid who eats the whole cake and then cries because it's gone.

I tried to be the best in the class. Now I'm the worst and everyone laughs at me. I'm a daggnix.

I took my dog to the park. He ran away. I'm a daggnix.

I tried to impress my boss. Now I'm getting fired. Classic daggnix.