Confidence comes from within. I can't say how you can be confident cos that's personal to you. But there is a link btw low self esteem passivity and stress and depression. Being confident is something we can develop, it is not forced but a lot of people appear confident when they are not rly. Its about having greater self worth value and care for self as well as engaging well, having harmonious healthy relationships . Assertiveness is really important too, can help a lot in reducing stress, preventing or overcoming depressive/anxious periods, by adopting more positive thinking and responses to negative or difficult people and situations.