My father is in his seventees he forgets everything and couldnt identify even his children, please what can we do to save the situation?

Possibly a dementia: It sounds like a somewhat advanced dementia. To say which type is impossible without many more facts, but in any case, try to have a doctor evaluate him and try to maintain calm - in him and others. Some types are reversible, most are not and many progress either slowly or rapidly. So, a doctor is essential to help you all understand. Best wishes - this is very hard, but it can be done.