Transfer Purchases to New AppleID

I opened a new AppleID with a new email address. Recently finished a divorce, and unfortunately, she went through apple to change the email associated with the iTunes Purchases. Although it was my email address, she somehow managed to get it changed. But I've never tried changing the iTunes Apple ID to my new one.

If I change the iTunes store apple ID, will I lose my purchases all together? Is there NOT a way to keep whats on my phone, and login with a different account moving forward?