Since apparently I'm a big meanie head, I'll tone down my reviews and talk to you about pieces you've done that I actually like and suggest some basic things you can do to improve all works you do from your deep meaningful pictures to cartoons.
I really like this one. You chose a complimenting pallet, the character's body language flows properly, I like the odd proportions and the expression is great. I would advise removing the pencil shading under the character with a digital one and picking a different shade for the eyes.
It finally dawned on me that your style is very similar to Sonic with the enlarged eyes, feet and hands. It was the eyelashes that made me realize this. It also reminds me of Bleedman's style, especially his early work.
I do agree with what you said that your traditional art is better than your digital work. Speaking of, what program do you use? Do you own a tablet? If you are more interested in improving your digital work, I would suggest looking up ways to create clean outlines and make your shading not as bumpy. Flash is actually a good program for beginning artists just doing still drawings, not just for animation. However it is good to see you are using cel shading and not the typical burn/doge technique, something I myself am guilty of when I first started out.
My best personal advice is to get a good sketchbook, a range of B2 to B6 pencils and take a trip to the park or a ride on the bus and sketch down everyone you see. You'll learn so much about the human form and how different every face is. It's amazing how just the size of the eyebrows or how big a forehead is to change the very personality of a character.
We've all been through that phase of thinking your work is perfect and above others, my time was actually when I drew similarly to you as a matter of fact. I think you just need to cool down, take a few steps back and remind yourself you can always improve. Every new piece of work is better than your last and with every new pencil stroke you learn something new. Hopping on the mindset that your current work is your very best or meaningful is very toxic and leave you big headed. Being humble and listening to others, no matter what they say will give you a new perspective.
You have potential. Don't let that go to waste by drawing the same thing the same way and take the advice of others. I guarantee you're going to look back one day and go "what was I thinking?!?" I hope you can forgive my initial bitchy comments and revisit the forums. I admit I can be a pushy asshole when it comes to people ignoring principle concepts but I should have toned it down. Just take the time to learn some new things and remember that art is suppose to be fun! You know you've gone wrong somewhere when drawing becomes a chore. So practice, practice, practice!
You guys exercised a lot of restraint, too. Goddamn.