It sounds like you have already answered your own question. Regardless of whether or not your relationship with Tyler continues, it seems time to make some new friends. Look around, there are probably other good people whom the "popular" crowd has disregarded for some reason, get to know them, and you may find new friends. And do talk to your (former?) "Best" friend, if she cannot explain anything other than Tyler being disliked because he has some self-confidence, then she may not be worth it!

And, of course, silly girl - you have friends here at Pet Talk! - so you are never truly friendless!