Keep working on that anatomy! Like in my own work, I see a lot of issues with your anatomy and relative perspectives. We did not see the legs and feet of your character once; is that just a coincidence?
The line work is a little thin for my taste and the backgrounds leave much to be desired. There is a Mike Judge feel to your art (I am not sure if that is what you are going for). The sequential/story may lose your reader a bit and comes across as weak - I am sure that we are just missing what precedes and follows what we are currently viewing.
Personally, I would worry less about keeping up with the professionals, making it in the biz, etc..., and more with getting the basics of illustration down. You have some work ahead of you!
Keep at it!!!