First, you might want to try hypnosis. You can find some for free on the internet (google Wendy Friesen Ultimate Confidence). It can help you achieve greater confidence. There are even some specifically designed to give you greater confidence approaching women. I have not tried this myself yet, but I've heard positive reviews from people I consider reliable.
Second, let go of the outcome. Trying to get yourself in the mindset that being rejected by stranger girls is as significant as losing in a video game. It is, but getting to that mindset is not easy. Write it down on paper, in your own words, and read it before you sleep, dozens of times, for a week or so. To drill it into your subconsciousness.
And, as Roosh suggests, for the first several dozen approaches, imagine a negative scenario, and approach. Imagine that a girl already thinks you're a worthless loser. Strongly enter that mindset. Play out the worst possible scenario in your head dozens of times, feel yourself present there, play out the worst possible emotions in your head. And then approach expecting the worst. It will almost never happen, but you will be prepared.
Do all this, and your AA should at the very least, lower significantly.
Second, let go of the outcome. Trying to get yourself in the mindset that being rejected by stranger girls is as significant as losing in a video game. It is, but getting to that mindset is not easy. Write it down on paper, in your own words, and read it before you sleep, dozens of times, for a week or so. To drill it into your subconsciousness.
And, as Roosh suggests, for the first several dozen approaches, imagine a negative scenario, and approach. Imagine that a girl already thinks you're a worthless loser. Strongly enter that mindset. Play out the worst possible scenario in your head dozens of times, feel yourself present there, play out the worst possible emotions in your head. And then approach expecting the worst. It will almost never happen, but you will be prepared.
Do all this, and your AA should at the very least, lower significantly.