My Sister: The One Who's Been There Since Day One

Times pass quickly, and there is no one that may not accompany us forever. So we must sincerely cherish every moment we are together with our loved people. I have a sister who is older 4 years old than me. As time passes by, we grew up with each annoyance. We extended our social circles with multiple people, which meant that we were alienating each other gradually. So that we decreased the times of communication between us.
When I stepped into the senior school, a sense of confusing flooded over my body. Unknown classmates, unfamiliar teachers and unaccommodated study content were like noises which I could not dispel lingering around my ears. However, my heart chasing perfect behavior still forced me to make ideal social relationship. In the end, I didn't do one thing excellent. The classmates were unwilling to play with me due to my bad temper, the teachers were sick of my ceaseless complaints and my study grades were unsatisfactory at all.
At weekends, I was eager to talk with my sister and express my trouble. But she seemed like a stranger. She angrily scolded me to get out of her room with a terrible look. I couldn't understand what happened but received grievance somehow. I blamed her for all the problems although I totally knew that was unfair. After the dinner, she asked me to her room with an unspeakable glance. When I got into the room, she embraced me and burst into tears. She apologized to me and explained the whole thing.
The day continuing, our relationship becomes more steadier. She teaches me something that school wouldn't teach and I also narrate the interesting thing happened around me, which is like that we were watching Tv leaning each other in the childhood. Annoyance disappeared with the hearty words said out as well. Thank you, my sister. It's you that taught me to be brave and strong.