Yikes.... A cut like that would take a while to heal. The endoderm to heal first; THEN the epiderm. You need stitches, really. That cut goes all the way in and you could get nastily infected. See a proper doctor. Two weeks is not a reasonable time for you to expect that to heal. It could take up to six weeks before it really gets better, and that's WITH stitches. Leaving it open will make it take MUCH longer.