For the Spirit that God has given us does not make us timid; instead, his Spirit fills us with power, love, and self-control. 2Timothy 1:7
If you want to find out how to be a confident wife, the first thing you need to do is to make sure that you're a confidant woman. Believe it or not, most men don't like insecure, frightened little mice for wives. Having someone who is so afraid of losing you that they'll do whatever you tell them to do is boring. Instead, keep his interest by being a smart, independent, and loving woman. If you do that you'll keep him loving you forever.
Now, of course, we all know that there are some guys around who like to bully their wives. The fact of the matter is they do this because it's them that feel insecure and they aren't confidant men. They think that by being 'in control' of their woman it makes them more of a man. The truth is that if you are with that kind of guy it won't work to be independent and confidant, that will just threaten him and probably make him mad. But, if that describes your guy you really have to ask yourself why a confidant woman like you would even want to be with someone like that.
If you find that you are a woman who gets jealous easily and that's the area you need to learn how to be a confident wife in, than there are a few questions you have to ask yourself:
Why are you so jealous? Do you have reason to be? Is your husband one of those insecure types who gets a charge out of making you jealous? Have you been cheated on before? Or, are you just insecure and unsure of yourself so you don't believe anyone could really ever love you? Find the reason and fix it. For many of these issues the best thing to do would be to go to a counselor to find ways to get past these issues you have. That way you can bring a stronger you to your marriage.
Once you figure out where your insecurities come from, from you and your past or from something your husband is doing, you can combat those insecurities and get to a better place.
If you used to be confidant in yourself but you now find that you're very insecure but only in terms of your relationship, it could be that you're sensing that you and your husband are on different levels when it comes to the relationship. For example, you might sense that you need him more than he needs you. It could be subtle, but if you feel that way it's natural that you'd respond with insecurities and uncertainties.
If you find that's the situation, you should talk to your husband and try to establish where he is. Once you know that you can compare where he is to where you are. It's highly likely that you are misreading things altogether. Guys show their love and affection differently than women. Find out for sure before you overreact.