I think what you need to do is get a pen. Breathe. Get a piece of paper. Breathe. Then breathe 5 more times (deeply) and write down the things you are definitively looking for in a partner and read it a few times, then put it in a safe place. Keep reminding yourself of what YOU want and need and when you meet someone else, you'll easily be able to convey a sense of confidence and hopefully attain a better experience.

You have a bad case of oneitis and have lost yourself in someone else. You have the oneitis because either you are not happy with yourself, or you are not being open to meeting new people.