You first need to find out what is causing the condensation.
The causes are going to be:
1) EXTERNAL, either thin external walls without insulation, probably east or north facing this means that the walls get very cold inside and any internal warm air hitting the walls causes condensation or solid walls facing probably facing west that get the brunt of rain, so that the walls are getting soaking wet and the condensation is arising from water evaporating from wet walls. The answer to both is likely to be wall insulation.
As it is a block of flats it is unlikely you will be able to install external insulation so internal insulation is the solution. You will need to get a builder to line your walls with insulated plasterboard or frame them up, fix slabs of insulation the wall and then plasterboard over them. If you are on a benefit of any kind; Pension Credit or a disability benefit or if you income is just above that level it is possible you can get this done through one of the Energy Company/Government schemes.
However if the problem is water penetration, all other flat owners on the same face of the building as you will have the same problem and you should contact the management of your flats about the wall being treated from outside to stop rain penetration.
2) INTERNAL. This is probably the more likely cause as you say your double glazing is fogging up. It is caused by either excessive generation of water vapour in the house; drying washing indoors, unvented tumble dryers, using stand alone Calor gas or similar heaters that generate a lot of water when in use or inadequate ventilation. Do your double glazed windows have trickle vents along the top of the frame. Are these closed or blocked? While it is good from the heat conservation point of view to reduce the number of air changes each hour, take this too far and you get condensation. Buildings built to be highly energy efficient also have forced ventilation and heat exchangers to keep condensation down. You will need to find ways to ventilate the flat, extractor fans of some kind in the kitchen and bathroom are the best solution, using them and keeping the doors to these rooms shut when in use.
Sorry for such a long post but with a condensation problem as bad as yours sounds. The only solution is to find the cause of the condensation and remedy that. Apart from anything else the conditions you seem to be living in now can be very bad for your respiratory health.
