Dear Dateless You are very insightful and actually have your problem figured out. You have a mindset that says pretty women get the guy. Your own history has proven that to be so. And, since you never felt as pretty as the girl who stole your daddy's heart, you have it figured that you aren't worthy of finding your Mr. Right, let alone a date.
The question is how do you break free of this cycle?
You really need to reprogram your mind. There are many ways to do this. You can do cognitive therapy. You can do hypnosis, which is designed to literally alter your neuroassociations.
You can also try self-affirmations, which is like self-hypnosis. With self-affirmations you are actually reprogramming your mind all by yourself. To do this you reiterate positive statements to yourself. The idea is to replace your current views with healthier ones.
Note that all affirmations are stated as 'done deals' meaning you don't talk about what you want to have in the future, but rather speak as though what you desire has already occurred. For example you might say: I am swamped with dates.
You might also create affirmations that counteract your belief that only knock-outs get dates. This affirmation might sound like, 'I am attractive enough to interest many different men.' Post your affirmations on the fridge and on the bathroom mirror, and say them out loud in the morning, throughout the day, and before bedtime. Then, sit back and start numbering your dates.