This sounds awful. My instant reaction, not knowing sufficient in cases like this to advise, would be to see your GP and see if you could be signed off with illness to let you take stock. Maybe try to objectively look back at the lesson observations and see what was found 'not good' so that you could address those things. Perhaps a friend or previous colleague could help you. If redundancy has been offered, maybe it's simply a case of there being insufficient money and trying to get rid of those last in... I would also go back to my union rep too and speak to them - is this the school one or the area rep? Go for the area one or phone the union direct. Good luck and thinking of you.