My parents had my youngest sister when I was 17. Helping care for her made me feel older than my peers.

• I was 17 when my youngest sister was born.
• Helping my parents care for her caused anxiety and strained some of my friendships.
• Therapy and some time away from home has changed our relationship for the better.

"I feel like she is my child," I said out loud to someone my age for the first time. It was 2014, and I was about to enter my final year of high school. I was sitting in my purple room, on my purple chair, talking to a friend about my baby sister who was just seven months old at the time.

She bursts out laughing. "Your child?" She guffawed. I was slightly startled by her reaction. After all, the adults I had shared this sentiment with had always seemed to appreciate how caring and helpful I was being. This was the first time that I realized that my circumstances might be alienating me from my own peer group.

I cared for my new sister in a different way

We had been a family of four — my parents, my younger sister, and I — for so long. But when I was 17, we added one more.

When my youngest sister was born, I became severely attached to her and seemingly took on the responsibility of being one of her caretakers. My parents were relieved as the amount of help I was providing made things a bit easier for them, and I essentially became a what felt like a third parent for my new sister.

In school, I would spend all my time talking about her, missing her, and worrying about her. I didn't realize it at the time, but to spend more time with her, I had begun to skip hangouts with my peers and even lost a friendship.

I remember my best friend at the time texted me, "It's okay. Your life is different now. You are Meredith and I am Cristina." This was in reference to season 10, episode 5 of "Grey's Anatomy" during which Cristina practically tells Meredith she has fallen behind in her career because she had kids. Ouch. It has been more than ten years, but I still remember that text.

School gave me some distance, but not less stress

When I left for college in a different city (an hour away by flight and 12 hours by bus) my sister was still top of mind and the concern I had about her stayed with me.

"You have a mother's anxiety," a professor told me when she saw how anxious I was when I heard my then 4-year-old sister had a cold. I took an overnight bus to be by her side.

I was emotionally invested, but something had to change

While helping to care for my sister was a decision I made, I also saw that I was starting to miss out on important things. I eventually realized I was abandoning my own friends and the fun I was supposed to be having while at college, and I was also distracted academically.

Over time, I was able to get myself back on track. Through therapy, I recognized that I was facing caregiving fatigue. I became more protective of my time and the assistance I could give, and had many conversations with my parents around these issues. The change was gradual, but my whole family was able to navigate our new relationships with one another.

Today, our relationship is different

In the past 10 years, I've been busy focusing on myself. I've built a career, had jobs, and went for my master's degree in London.

Now, my parents parent my sister, and I trust that they are doing a good job. After all, they also raised two other kids.

I am back living with my family again and my relationship with my sister is more sibling-like than caretaker. If you would have told me ten years ago that this is what our future would be, I would have been devastated. But as of today, with friendships, a career, hobbies, love and travel, I am glad for the demotion. No longer a part-time mother, I fight, laugh, and play with her like any sibling, and my parents take care of the rest.