I am too shy around a guy I kinda like. Please help me!?

I am 16 years old and I have never been shy around boys I'm interested in before. Usually when I like someone I always try to do anything and everything to get their attention to notice me. But not with this guy. With this certain guy, I am SUPER shy around him. So shy that I refuse to do almost everything..now I am usually not considered a shy person. I am one that is outgoing and spastic. The boy kinda likes me too but he says he wants to see me stop holding back. I don't know what to do..every time we hang out I always go into shy mode. I don't like it. I get self-conscious. Then after we're done hanging out, I become saddened that I didn't break out of this shell and feel ashamed of myself. What should I do? Please help me!