Try not to beat yourself up over drawing. If you enjoy the process of learning, keep trying.
I also get frustrated at times trying to use the tools for optimal results. That's why my drawings take a while.
I have no problem working on a draw, saving it, and trying later if I get frustrated.
Fresh eyes later on can take on a whole new perspective. Have fun learning!

What applet are you using? Maybe you're pressing some wrong key or something? Maybe scrolling on the touchpad by accident or something?