you was forced into becoming what?
Being self-employed again. Can't you read English?
£26000 salary, + Expenses, 25 days PAID holiday, Flexi Time, Paid Sick Leave, Final Salary Pension + intellectually challenging work (I.T.).
Daz
£2600K
Window Cleaning and being your own boss is O.K. but it's hard physical work, battling against the weather, it has it's ups but it has it's downs.
If it's all you can do because of your skill set and education it's better than minimum wage but it's still cleaning after all, a job anyone can do.
"Forced" because at 58 trying to get another job in I.T. is a waste of time you're a dinosaur in I.T. at 28 let alone 58!
Good thing about window cleaning is you can throw the ladders on the car, squeegee, applicator couple of scrims, get knocking and even on the first day you'll come back with something to put bread on the table and pay the rent.
£26k a year is not a very good salary IMO even with holiday/sick pay and expenses,etc.i earn a lot more window cleaning 30-35 hours a week 10 months a year. 
£26K is the base line, you bang on about how much you earn but you still live in a council flat.
You will still be paying rent when your body is F *** by hard physical work window cleaning and you'll still have the rent to pay when you can't work, with no pension.
Self-employment is free and easy on your time but never underestimate the value of a regular salary with benefits, try getting a mortgage now as self-employed and buy yourself out of the "generation rent" trap.