Focus on self is the problem whether you're insecure or overly confident...
Are you suffering from low self-esteem? God has the answer.
Are you proud of your high self-esteem? Don't be.
Our culture believes high self-esteem is good, but God says neither low nor high self-esteem is desirable. Instead, we need a realistic, balanced view of ourselves, based on our faith--i.e. our esteem for Him.
"For by the grace given me I say to every one of you: Do not think of yourself more highly than you ought, but rather think of yourself with sober judgment, in accordance with the faith God has distributed to each of you." Romans 12:3
The way to achieve this balanced view of self is to quit focusing on self altogether (Luke 9:23-24) and follow the priorities Jesus gave us in Mark 12:30-31:
"Love the Lord your God with all your heart ... ‘Love your neighbor as yourself.’ There is no commandment greater than these.”
No greater commandment and no greater cure for high or low self-esteem.