Kev
So much of what you have said is familiar to many of us. You are not alone. Stick with it. It is worth it in the end.
My own situation was also protracted, although not nearly as much as yours. And my true interest in flying started thanks due to the RAF GSA. Thanks guys for that.
A quick look at my logbook for my 'official' PPL training shows the following facts:-
total time taken - 6 1/2 years
total hours taken 84 hours
total number of instructors 12
total number of flying schools 3
total numbers of aircraft types 11
Made it in the end. And yes it was worth the trials and tribulations.