It is very easy to solve your problem. You need a little practice, that is all. Do Steps 1 - 10 three times a week, until you have overwritten your past conditioning with more positive patterns of thinking.
How to Perform Self Hypnosis - wikiHow
For Step 7, instead of using positive statements, you may wish to visualise, say, a scene where you are talking happily and confidently with a group of girls who are obviously liking you a lot.
(For those who know about the Law of Attraction, you know that this modified Step 7 is going to do a lot more than just promoting self-confidence. Better not visualise any unattractive girls.

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