First of all, thanks for your frank and honest posting. I hope to god you have moved on from this training centre hell.

A couple of things though in your post:

It was the beginning of the economic crisis, and jobs in London were scarce. Family members of mine had been laid off work, and I had just graduated at an awful time in … , after my degree and CELTA course. I took the CELTA knowing that I will be able to work abroad and that will hopefully offset any issues regarding job hunting in Europe.

A CELTA is not really necessary for China. With those quals you could have got far higher paying work elsewhere, and with less stress. You left because you wanted something better, and that is admirable. But next time look around, Taiwan/the gulf, all pay much better and with more benefits.