Believe in yourself

You asked "how do you make others believe in you?"

The secret is to first believe in yourself. The more clearly you do that the more others will believe in you. Focus on you believing, rather than them believing.

"Is self confidence enough?"

If your self confidence is based on your understanding of yourself that is very powerful. Those interviewing you pick that up from you as soon as they meet you. No matter what you ability, if you do not have confidence in your ability, others will not either.

It is not what you say, it is what you are being. People will pick up on your quality of being rather than your words. Self confidence comes when you acknowledge and accept your
strengths and your weaknesses.

If you have confidence in others, they will have confidence in you.