how to present a uiviewcontroller over a spritekit scene

Hi I have seen many questions about this topic but none seem to solve my situation. I want to present a UIView controller over an SKScene when the user win/dies. I created a PresentWinLoseViewController : UIViewController subclass and connected it in story board. I created a segue from GameViewController to PresentWinLoseViewController in storyboard plus two exit segues from PresentWinLoseViewController back to GameViewController.

Here is how I am calling these. In my SKScene when I win/lose

func win() {
     let gameVC = GameViewController()
    gameVC.performSegueWithIdentifier("tryAgain", sender: self)
}

and my exit segues from PresentWinLoseViewController

   @IBAction func tryAgainButtonPressed(segue:UIStoryboardSegue) {

    self.performSegueWithIdentifier("unwindTryAgain", sender: self)

}

but I cant even get that far bc the first segue never works. I keep getting

Receiver (<SpriteLevelBuilder.GameViewController: 0x7ff2b5e49210>) has no segue with identifier 'tryAgain''

what am i doing wrong?