Ummm.... The whole idea behind telling yourself something until you actually believe it is something I wouldn't recommend. First of all, I doubt it would work effectively in the long run. It could work, however, the person you would become is the kind of person I don't respect much.
First of all, for it to actually work, you will have to actually be convinced that you are who you say you are. Your mind will actually have to believe that you are that attractive and that you are that stud that women would want. Any doubts that you may have would render this whole exercise a failure. And these doubts will most likely occur if you're not good at brainwashing yourself as it is extremely difficult to be 100% successful with women. If you've got no doubts, then how you handle the rejection is important. Blame the girl, and you'll be blaming women the rest of your life. This is so because to blame someone else is to put the prerogative to change on someone else instead of on yourself. If you decide to change because you're the one that has to improve, then you didn't exactly convince yourself very well that you're all that jazz.
In my opinion, the understanding of human behaviour and human nature is a better way of changing your mindset. You have to realize and accept your place in this world and work from there to better your position. Not every girl is going to treat you nice and be the kind of girl you want. Some can be rude, some can ignore, some can string you along, some can just use you. This is just the way human beings are. You can't change this but you can change the way you expect things from them.
Never expect others to treat you with dignity and respect. You can only think that they will. And if they don't, it doesn't come as a shock or something that has to devastate you because you've already understood that these kind of people do exist and you already know how you're gonna treat them. The reason a person gets devastated is because they take it as a personal attack or insult. It's as if this person doesn't like me, no one will. If you seriously believe this, then the only advice I have is to actually surround yourself with people that like you. Allow yourself to understand that you are likeable, but just not to everyone.
You could always be full of confidence and talk about how good you are and shyt like that. But if you ain't got the consistency and results to back up your talk, no one is gonna respect you. The phrase, "You talk the talk, but can you walk the walk?" explains this.
Whether or not someone wants to trick you is irrelevant. What's so bad with being tricked anyway? They could very well want to kill you. Or rob you. Or marry you and take all your money. Or fvck your good friend. Or embarass you in front of everyone. Or get back at they ex by making them jealous. There's so many shyt that people can and are capable of doing. If you want to protect yourself from all this, I doubt you would enjoy yourself very much. You are what you believe you are and not what you tell yourself you are. And if you believe you're this pathetic loser that has no self-esteem and low confidence which every single girl on this planet is trying to trick, then that's exactly who you are. If you don't want to be that person, then believe you're better than that.