I hate when authors make teenage characters overly angsty. Yeah, we have hormones, but stop laying it on so thick. None of my friends are ever that woe-is-me.
That's all right, as long as none of the information you just gave is given in the story. That's the point where this thread should be focused: Good - The reader is able to describe the character as you just did. Bad - The reader is able to point the paragraph where one can read "He turned all his angst inwards, making him bitter and angry instead. He turned his depression into strength. A strength that pushed people away." It's quite easy. I'd just put the story in the word processor and run a search for "angst", "depression", "hurt", "angry", "bitter", "sad" and any other I could think off. Then, I'd remove all those fragments and reread the text to see if the reader would still understand the character as I do.