@Pere "Show Your Work" by Austin Kleon is exactly about building an online presence.
Your work doesn't even have to be great. It has to be good and it has to improve. Well, it also has to be original. The most valuable advice I can give is to go slow and steady, start small, enjoy the tiniest achievement and be smarter than the competition. For instance, make a list of 50 best ideas to improve your art and market it better. Try every single one. If nothing helps, which is unlikely, you can always find another 50, and so on.
You're in the right place, just keep going.
And yes - add links to your work in your profile description so everyone could see it.