If you are starting out to learn a new skill, or starting a new business, or trying something new, know that everyday isn’t a copy of each other. Otherwise life would be boring.
Therefore, you may have a more successful day today or less successful one. Always thrive for success. Keep in mind, when you have problems, your enthusiasm might fade away (this happens to all of us, at varying degrees).
So what do you do, along your effort of making things better (than yesterday) ? You also motivate yourself. Motivate yourself by watching the people in that field, whatever that is.
If it is a skill you are trying to acquire, watch the pros in that subject.
If it is a business you are trying to create or you just started your business, you can read about other people who also started and succeeded.
With communication being easier than past, we can connect to people and listen to their success stories. Some ways we can do this, online, via books, videos, audios etc.
Speaking from my own experience, by watching successful people, you can have a complete turn around and regain your enthusiasm. Carry on!