Popa- your diagnosis may be accurate but please admit you never would have thought of it if not for his screen name.
Gilgul- You absolutely CAN lose your Bashert. The Steipler told many older singles that they turned down their Zivug. But as long as you make correct decisions based on common sense and ask Daas Torah if you have a question, you’ll be fine.
Rabbi Perfect- I must take issue with what you wrote that you don’t want to cause pain especially to a girl. Unless you meant that a girl is more likely to be hurt, it sounds to me like the secular notion of ‘ladies first’ being nicer to women, which is contrary to Torah values. See Horiyos Daf 11
As for your issue I also feel bad for my rejects. But is it better to go out 8 times and then say no? Is it better to break an engagement and or a marriage Ch’V because the Shidduch was ill-conceived? Obviously the girl would rather you break it off earlier. To make up for the inadvertant pain you caused, you can Daven that they meet their true Zivug soon