Problem with shared Apple ID

So, originally when I first made an itunes account it was shared between my brothers and I under one of their Apple IDs. But, now that brother has gone off to college and wants to have a seperate account. So, he made one and will not share any longer. But, now I am free to have my own account without any of my brother's bad music on my phone.

I made a new Apple ID and have already purchased some songs, but I am faced with a major dilemma. Because I had my iphone linked to another ID and computer, if I sync my phone to my laptop on my new ID I will lose all of my music. Which, wouldnt be so bad if I didn't pay for most of it. This whole situation has been frustrating me to no end and I really need the help.

So, I was wondering if there was ANY way to sync my music on to my new laptop and Apple ID since I paid for most of those songs with my money, and would like to keep them?