I do not want to change my Apple ID

I do not want to change my Apple ID but it says I have to change it. I was on the family I PAd and I tried to put in my iTunes password but it didn't work because the iPad was attached to my husband's email account but I didn't know that (he changed it). After I linked it to my email account, it won't let me use my ID but says I have to create a new one. I am up to here with creating new passwords. Also, it acts like iTunes password and Apple ID are always the same, are they?