How can I hide my nervousness around a woman? How can I fix my

What makes you nervous is taking yourself too seriously and thinking too much about what she thinks (or will think) of you. Shyness can't be fixed or hidden - you simply have to disregard the negative thoughts your mind is telling you. Approaching women quickly, more often, and without thinking about what you're going to say first will strengthen your resolve over time and deminish those types of thoughts running through your mind. Never approach a woman thinking "I must absolutely make a good first impression or she'll never..." Instead think, "I wonder what she'll do when I tell her X, Y , or Z" and don't worry so much that she might not respond the way you want - most women won't. At least not until you've gained rapport and a chance to lead the onversation (and her) in the direction you want to go.