If you don't sell your time or use your time efficiently, then you simply cannot earn the kind of income that you want to earn. Learn to love your work and commit yourself to becoming outstanding in your field. You will have many ups and downs in life, but what is most important is that you remain true to yourself. The starting point of developing a high level of self-confidence is to think through and decide upon your values. Winners get there early, they work late, they work through their lunch hour, they work through their coffee breaks, they work in the evenings, they study on the weekends, they take extra courses.
Winners are absolutely determined to win, and they are willing to pay the price.
Take the time, pay any price, do whatever is necessary to become the very best at what you do. Back every goal and plan with persistent determination and indomitable will power. You can never really feel terrific about yourself, you can never really like yourself genuinely and accept yourself as a worthwhile person, until you have become good at what you do. The reason why the vast majority of people are unhappy is that they are not good at anything. Your level of persistence in the face of adversity, setbacks, and disappointments is your exact measure of your belief in yourself.