Tense form of the verb

Hello,

1. My father ---------------- his memoir when he ---- a heart attack.(write , have).

Ans. My father had been writting his memoir when he had a heart attack.

or

My father was writting his memoir when he had a heart attack.

Whic one is correct?

2. We ------- a wonderful time. we --------- the Himalaya for a whole month. ( have, trek)

Ans: We had a wonderful time. We had been trekking the Himalaya for a whole month. ( have, trek)

or any other alternate?

3. I ---------- the day I had first visited the city. I ------------ in a village for 10 years before that. (remember, live)

Ans : I remembered the day I had first visited the city. I had lived in a village for 10 years before that. (remember, live)

Is this correct?

Thanks.