Discussion questions technique

Hi tutor,
The nerves are really setting in now!

When it comes to discussion questions within the exam I often find that I am wasting valuable time trying to introduce the topic and set the scene before really getting into my answer.
How do I stop myself from wasting valuable time so I can just get down to addressing the scenario in the question?

1 more cheeky question….
What would be your advice to tackle the often neglected Question 4 when you realise that you are running out of time and are not able to allocate the 1.8 minutes per mark to it as required?

Thanks for everything Opentuition!