How can I turn off sharing contacts?

My fiance and I have 1 iTunes account. I updated both of our phones, ipad and Mac with the new update. Now we are sharing contacts, we don't mind sharing everything else, but we want our contacts to be separate. Everytime I turn off the contacts, it deletes the entire contact list including my own. If I delete his contacts from my phone, they are also deleting on his phone as well. Is there a way around this?

Alicia