it usually takes a while before people find you. I've been here for more than a month and i only have 2 people that regularly comment on my things. I suggest posting your works into groups and also to comment on other people's work and simply to get known around the DA community
Don't get too discouraged. It happens to a lot of us. One way to get feedback is to submit your work to some of the specific graphic novel groups. You can also try the Thumbnail Share here in the forums.