I remember when folks just eyeballed the salt for fermenting, and it usually worked out. My kraut was always too soft, so I started measuring everything. Turns out, using 2% salt by weight of the cabbage gives consistent results. It's simple, but it took me a while to figure out.
Try keeping it around 65 degrees if you can. That slower ferment really does make a difference for the texture. I left a batch in my cool basement last time and it was way crisper.