In today's "Since you asked" column by Cary Tennis, I found good advice about making art:
"Now, therefore, should I draw or should I write?
The answer, as always, for an artist, is to pick something and get to work. If you have a piece of marble ready to work on in the basement, and you have your tools, then go to the basement and start working on the sculpture. If you are sitting at a desk and you have paper in front of you, start writing. If you have tubes of acrylic paint in your taboret, and there is good light, and you have a canvas stretched on your easel, then paint.
What happened to you in the painting class interests me. As we work we are often flooded with uncomfortable feelings. As we work we learn to know these feelings and use them. Creative work is exhausting. You must train for it. You must stay in shape. Life drawing is hard. At first you will feel exhausted. You are using a part of your brain that has not been exercised lately.
So be careful not to misinterpret your exhaustion as an indicator of your talent or lack of it, or of an innate disposition toward this or that medium, or as a mystical sign. It is more physical. It is more about the work. Your exhaustion and fears and technical limitations are just hurdles to overcome. The vision and the determination are what count. So focus on what you want to create. Do not focus on your technical ability or lack of it. Focus on your vision and work toward it. As you work toward your vision, let it show you what technical skills you need."