This "debate" was an utter mess and Trump; didn't help himself any. :-(
We're all going to vote that he won, which he didn't, but he'll believe that he did and THAT is NOT at all helpful to him.
Not necessarily. With over 2/3 of the people distrusting the media, but (from what I’ve seen) more or less believing the aggregate of polls, a public perception that Trump did at least ok may be good enough. And I suspect DT is plenty smart enough to, on the one hand, say publicly “Look at how we did in poll X, Y, or Z!”, and in private, with his advisors, plan the next steps.