I do this too, I seem to want to get close to people instantly, if I don't see the immediate reaction from them that they are interested, then I just give up and consider that they don't want me. I sometimes try a bit more just to torture myself and then conclude that I'm not good enough for them.
People do get scared off by wanting to get close too fast, apparently, but we do this maybe, the wanting to get close fast, because we need the reasurrance that they will like us.
You seem to be a really sensitive person and in need for a deep emotional connection and I believe that there are people who will honour that and who will meet your needs and make you happy, and love you for who you are. I know it seems impossible to find someone like this, but I believe that if we try to honour ourselves and accept ourselves (which is so hard) then there is much hope.