Dealing with nerves

Hello everyone! I need help!

I started my new job on Monday as a Sales Apprentice for a ISP who specialise in bonded connectivity.

Basically, as a Sales Apprentice, my job eventually will be to speak to people who ring up and our interested in our services. I sat down with my boss Wednesday and we went through a basic sales pitch I'd be working on, he wants me to eventually learn it off by hand - no problem, he knows it'll take time and he knows I'm not going to learn it within a few days.

He asked me to read through the pitch when I got home and to do my best to familiarise myself with it so that I know how to say things and what kind of things will be coming up in the pitch.

However, he asked me to Pitch it to him and I completely lost it, I got so nervous and ended up rushing through it and messing it up. He knows it won't happen overnight, so he wasn't that bothered - but I wanted to try and impress him so it looks like I'm really good considering I have no experience.

How do I control these nerves? I try to stay calm, breathe slow, take pauses, but it ends up with me sweating, red faced and messing it up.

Has anyone got any really detailed, useful tips?

Thank you,
Ryan