My computer is running on my sisters Apple ID?

I have a Mac Book Pro 2014. When I transferred music from my old Windows Toshiba some of it did not transfer and I ended up loosing it. To fix this I decided to sync my phone with my sisters account and collected the missing music off of it then transferred it to my account since the 90 day policy was not going to affect me very much. I also have a couple songs that I got from my sisters account that she had gotten from our fathers account. I have my computer authorized to all three of our accounts so that all the music works correctly. The problem is: I now cannot update my computer or many of the apps on it because it keeps asking for my sisters ID. It doesn't ask for mine or dad's. All my devices and my computer are set to run on my ID and it is only iTunes that has been authorized with the other accounts but is currently logged into mine. I don't understand why this is happening. I have also had some trouble with the music I have bought on iTunes not syncing because it is from an unauthorized ID even though mine is the primary ID authorized and used. I have even tried de-authorizing and re-authorizing it. Is there anyway I can reset my Apple account without loosing everything that I purchased? This has never happened before. It is ok if I have to loose the music I pulled from my sisters account, I can repurchase those if necessary but they are all working, only things from MY account are not and I can't find anything that is not using my ID so there is nothing to change. I think I have to reset it but I can't loose everything, music will cost a fortune and if a computer reset is needed then I loose all photos and papers for school which is not an option. Anyone know how to fix this?