We had the same problem. A boy that sounded amazing was redd to my daughter, by the time we said yes he was busy. My daughter started to go out with someone else that she was iffy about and in the mean time the first boy boy wasnt busy anymore but I told my daughter to forget about the first boy and concentrate on who she was going out with and guess what they got married and they are b’h so happy. I am not saying that this boy that is iffy will be the one, but if the first boy is your bashert he will be there when you are ready.
Another word of advice, never look back and think what about what if. It was not meant to be.
Hatzlocha