ITunes is adding a lot of music from my last backup whenever I add one new song

Question

So I am on my second iPhone and for years I have just managed my music manually. In itunes, syncing for music is turned off. Manually manage music is turned on. iCloud, iTunes match etc. are all turned off. I frequently add and remove albums from my phone without any incidents - until lately. Now whenever I add a new song or album to my phone, itunes also adds all the music that was included in my phone's last backup. So if I had like 10 albums on my phone when I backed it up, that were then deleted on my phone - it re-adds them. I can't for the life of me figure out how to get this to stop. The only thing that works is deleting all the backups on my computer. If i do that, the phone lets me add one album at a time. Otherwise it just keeps insiting that these albums belong on my phone. Again, i've gone through like every setting with a fine comb to make sure it's not an obvious check box that I've missed. Help?

Answer 1

The Three Best Alternatives for Security Questions and Rescue Mail
     If you do not have success with one, then try another:
        1.  Send Apple an email request at: Apple - Support - iTunes Store - Contact Us.
        2.  Call Apple Support in your country: Customer Service: Contact Apple support.
        3.  Rescue email address and how to reset Apple ID security questions.
A substitute for using the security questions is to use 2-step verification:
Two-step verification FAQ Get answers to frequently asked questions about two-step verification for Apple ID.