Is it possible that you are becoming too emotionally invested too soon? At the risk of repeating myself, my advice would be to go into these situations with zero expectations ... because with zero expectations, you will never be let down.
Take each date with one of these women as a one-time occassion ... be happy about being out with someone nice ... and don't think about the future any further than 10 minutes from the moment when you are with them. That reduces the pressure on them, and on yourself. Success does not necessarily mean a long-term relationship has been achieved - success can simply mean having a nice time with someone one evening ...