Head, Heart, and Hand
University of California developed a theory called the "3 components model of motivation".
It's easy to look at motivation as something that happens on its own, but we actually have more control over it than we think.
A professor from the University of California developed a theory called the "3 components model of motivation".
The 3 components are head, heart, and hand:
Head - "Is this task really important to me and relevant to my goal?"
Heart - "Do I enjoy this task?"
Hand - "Am I good at this task?"
Every time you want to do a task, enjoy a hobby, or accomplish a goal, head, heart, and hand come into play.
His theory says that peak motivation happens when all 3 components are fulfilled. So if one aspect is lacking, we'll have a hard time feeling motivated.
For people who are unmotivated in school, it's easy to be lacking in head, heart, and hand. School might not be important to your goals, you might not enjoy the work, and/or you might not be performing well.
For art, or any other new hobbies you're trying, try to find which component is hurting your motivation. Then you can address the issue by: finding a way to make it more enjoyable, finding incentives to make you do it, and/or training your skills.
I hope this helps you in some way!
Keeping this theory in mind has helped me get control of my motivation.