Although the three materials you chose are relatively ordinary and a bit cliché. But what makes people feel the warmth of true love in the world is often not the grand events, but the trivial things that happen around us. You described these three personal experiences in three parallel paragraphs, with fluent writing and beautiful language.
Here are some bones to pick from the eggs for you:
1) "All living beings in the world have lost countless desolations." Life is full of ups and downs. There are always many ups and downs, and countless winds and cold rains. It is impossible to end the desolation.
2) "Because of warmth, I got the key to the door to success." Warmth can only give you courage and strength, but it cannot let you "get the key to the door to success." Success must rely on your own efforts.
3) "With the mother's elongated figure gradually passing away in the moonlight," there is a lack of subject here, who "accompanies" it? Would it be better to change it to: "Watching my mother's elongated figure gradually leave under the moonlight."
4) "But my heart is warmer and more moved than usual." This sentence inserted here feels like a tree without roots and water without a source. It would be better to move it to the end of the paragraph.
5) "Blow gongs and drums", first of all, gongs are struck, not blown. Using gongs and drums as a metaphor for lightning and thunder is not appropriate here, because gongs and drums are generally used to describe liveliness and celebration, which does not match your mood at that time.
6) "I lowered my head in disappointment and looked confusedly at everything lifeless around me except Yu'er." How can you "look" by "lowering your head"? Why does a rain make the surroundings "lifeless"?
7) "Said happily", why is your friend "happy"?
8) After reading the full text, I only found one period.
Gorgeous words may not necessarily create a touching chapter, but sometimes they give people a feeling of being piled up and flashy. With all due respect, your composition feels a little bit like this to me - it's rather pretentious. Have you read Sanmao’s essays? Her works have plain language, true feelings and humor. Of course, you are a student and you cannot be asked to write an article like Sanmao. But we can learn from her writing style.
I am not a Chinese teacher, and I have never written any good articles. Maybe there are many fallacies in what I said above. Please correct me and forgive me.