Listen up man. This is how it is. You gotta be happy being single. If you can't be happy being single, in otherwords being yourself, what makes you think any girl could be happy with you. I have your same problem. Well had your same problem. You just gotta be happy being you. If you are happy with being you then that crap about "standards too high" will go away. If you can be happy being you then you will have the confidence to ask out any girl whether super model or super brain because you will know, no matter what, you deserve who you desire. When you can be happy being single then it won't matter whether or not you have a girl at the moment.
Now as for how to have this joy in being you you've gotta want to be happy first that's up to you, but try this. Remember you can have any girl you see and if she doesn't want you then you can do better than a girl who can't see how great you are. Sound conceded? Well thats right, but sounds to me like you've been too humble in your opion of yourself. Time to believe in yourself, and I mean really believe.