There is a mistake plenty of candidates make, and it does not happen in Part 2. It happens in Part 3.
Part 2 is about you
Part 2 asks you to describe something specific from your own life. Say, a healthy habit you have recently developed:
I have noticed a positive impact on my mood. Yoga includes breathing techniques and meditation, and they have helped me manage stress better, especially during busy weeks at work.
That is good. Specific, personal, with real detail in it.
Part 3 is not
Part 3 stays on the same subject but asks about the general case, not your particular instance.
If Part 2 asked about your habit, Part 3 will ask something like: why do many people struggle to maintain healthy habits? What could society do to encourage them?
The common error
Having just told their own story in Part 2, candidates carry straight on in the same mode: "for me, I find that...", "back then I...".
The question has widened out and the answer has stayed where it was.
How to fix it
When Part 3 starts, notice who the question is about. Words like people, society, young people, these days are the signal that you are being asked about the general pattern.
You can still use yourself as an example, but it has to sit inside a general claim rather than replace it.