No, it's not uncommon to want to protect the ones you love. I think it becomes an obsession when it's all you think about, which can be quite destructive to your relationship.

I'm guessing that your wife and T see it's a serious problem because you think that is your one sole purpose...to be the protector of your wife. While some women may find this to be romantic, it's hard on you. It will drain you of all life to be so focused on this.