How could I write without losing inspiration?

Dear Mr. Murakami,

You are my favourite writer and I cherish all of your works dearly. My mom recommended your books to me and to this day, I haven't stopped rereading Dance Dance Dance. Kafka on the Shore made me strong me when I was most down, Dance Dance Dance taught me to always dance and to never stop, After Dark showed me the secrets of the night and What I talk about when I talk about running inspired me to lose about 40 Kg. My question for you today is a complex one which needs me to explain myself a bit. I took up writing as a hobby last year and I've written a few short stories. The problem with me is that I keep stopping and thus, I keep losing the inspiration to write long stories. To summarise my explanation, how could I write long pieces of writing without losing inspiration? 

Thank you so much for giving me the chance to write to you, Sir.
(Ahmad 、男性、15歳、Student)

Thanks for reading my books. You’re 15 and writing stories yourself. Wow! You have lost 40kg. That is really amazing.

How can you keep on writing without losing your inspiration on the way? My suggestion is that you sit at your desk for an hour (or so) everyday, hopefully at the same hour. You can write your story there. But if you don’t want to write, you don’t have to. However, do not do anything else. Don’t read books. Don’t do SNS. Just sit at the desk, write your story or do nothing. Continuity is the key to your inspiration. That is exactly what I am doing everyday.

hm