Should I decrease the pressure in my tire to gain stability. It's really worth doing a few sessions of half an hour or so, which should speed up your learning with the longer concentration.
People learn in different times.
You may learn in a week, or it may take a bit longer, and it will probably take quite a bit more practice to be able to stay on for longer and steer yourself - you may get that in another week, or perhaps a month. I found that squidgy tires helped me a lot when learning - they slow you down and make the uni less sensitive to bumps and grit etc.