Moving all my music from pc to MacBook

[Stinky]

So I have bought myself a MacBook and am now trying to use that for my iPhone iPad syncing

However it keeps telling me it's going to delete all my music and put on the stuff on the mac! I have recently bought loads straight onto my phone! So if that gets deleted it doesn't come back! How do I get this off? I've tried backing up the phone but it's not showing on my iTunes library

 

[Stinky]

If you right-click on the phone in iTunes is there an option that says something like transfer purchases?

That's the one!

However it's now telling me I can't auth this computer because I have 5 others already! I've been onto my old laptop and clicked de-authorise this computer which it says is done but still won't allow me on the mac!

Any ideas?