Line between confidence and over confidence?

I see nothing wrong here. I mean, it's not like you were today's steve urkel and asked her out a thousand times. Three times is not unreasonable, especially if 1) her reasons were actually valid and 2) you detected sincerity in them. The 'don't hold your breathe' comment though would basically be the 'end all' for any future attempts.

I have found that being forward, while awkward, is fairly important. Confusing things make it hard to ever pan out the way you hope. Very rarely does being friends turn into a relationship. Usually, IF it does happen, AND it isn't something awkward, then both of those friends are fairly mature and it is after a huge amount of time.

Anyway, you did fine.

Jam it back in, in the dark.