Yeah, the best way to put it would be to stop caring how othe will see you and just believe in yourself. But that is so easy to say right? I know, I agree with that too. Well I guess it comes with experience. You didn't mention how long you've been playing basketball on that level.
That is so important. What can you do? Keep practicing to be better and better. There is no secret philosophy behind that. Don't fall for that new program that comes along telling you how to develop amazing, whatever-ability in 1 week. It's all work. It's all practice.
And you know what? I agree with Fallguy20 saying that it really depends on what you're afraid of. That's a valid point. You said that sometimes you are not afraid and sometimes you are. Well, instead of looking at those butterflies as a sign that you're weak, perceive them as a sign that you're actually getting better. Because that's true. You are. When you're most struggling you're getting better. That's not positive thinking, I don't believe in that kind of b.s. It's real.
There are a lot of free website full of tips on basketball and how to become a better player. You don't have to pay for that. I have such a website. It's at http://www.best-basketball-tips.com
And take everyone's advice. Learn from many people. You can go to youtube and watch the NBA guys play. Try to learn something from that.
Hope that helps,