I did a long spell for CAB as a tribunal worker , and the big mistake that many applicants make in their claims for benefits is , that they spend ages writing and talking about the things they can do and very little thought often goes in to the things they cannot do.
A benefits agency is not interested in what you can do , and judges your claim on the things you can't do.
So put self pride and the effort of being independent aside and tell it as it is -- what can you not do ,or what are the things which make your life difficult or painful.Good luck.