How do I handle the responsibility of managing other people's money?

You are feeling the truth of your work: the money you decide about is not yours. It belongs to people who saved it, worried over it, and trusted it to your care. That weight you feel is not anxiety to get rid of. It is conscience, and it is exactly what this work needs. Most people in finance learn to see the numbers and forget the person behind them. You are going the other way, and it will make you better, not weaker. A person who remembers whose money it is makes more careful, more honest decisions than one who sees only figures on a screen. Let that awareness shape one habit. Before a decision that affects someone's account, pause and picture the actual person, their reasons, their trust. Then act as you would want someone to act with what is yours. That small practice turns the weight into wisdom.