A simple fall back is to ask for a copy of everything as you go along. Every time you see a consultant ask for a copy of his letter to the GP and a photocopy of his notes. Every time you have a blood test ask for a copy of the results. Every time you have any imaging, the CD and report etc etc. Nobody can refuse these requests and in practice, apart possibly for the photocopied notes, they will not charge provided you ask at the time
The NHS is well behind on IT and is going down the road of importing massive systems from other countries that are mindbogglingly expensive and complex such that they are not solving the basic requirements for all an individual's notes to be in one place and immediately accessible.