One of the main reasons why people fail to achieve their goals in life is because of a lack of determination. It is determination that creates the other great cause of achievement which is persistence.
If you want to feel self-confident and you have focused in on that desired state of being you have to be determined that self-confident is the way you are going to feel all of the time. It is no good being determined some of the time and then allowing yourself a day off every now and then. You have to be determined all of the time.
So being determined is a desired state that supports your state of being self-confident. You need both of these states in order to succeed in becoming the self-confient person that you want to be.
In truth, nothing worthwhile in life is ever achieved without determination. I love determined people, those people who are prepared to stand up and fight for what they really want. People who stick to it until they achieve their goals.