Millie Bobby Brown was only 12 when she filmed the first season of "Stranger Things." However, since the Netflix series exploded in popularity, the young actress has endured inappropriate comments about her looks, body, and personality. Now, she's fighting for change.

Brown, who turned 16 on Wednesday, reflected on growing up in the spotlight and penned a fiery letter in support of protecting young actors. "I feel like change needs to happen for not only this generation but the next," begins the "Godzilla: King of the Monsters" star. "Our world needs kindness and support in order for us children to grow and succeed."

Brown then opened up about how the negative attention affected her when she was younger. "The last few years haven't been easy. I'll admit that," She explained, "There are moments I get frustrated from the inaccuracy, inappropriate comments, sexualization, and unnecessary insults that ultimately have resulted in pain and insecurity for me."

The now-16-year-old accentuated this in her video, set to Justin Bieber's "Changes," which not only contained examples of the bullying she's endured, but also how she's been hounded by the paparazzi since breaking into the mainstream. She titled the video, "The Truth About Millie Bobby Brown."

Despite the negativity, the British actress promised that she will remain undefeated and "always find a way to smile."

Wanting to spare future actors from the same experience, Brown vowed, "I'll continue doing what I love and spreading the message in order to make change. Let's focus on what needs changing."

Celebrities such as Octavia Spencer, Bella Hadid, Lauren Jauregui and Yara Shahidi were quick to support Brown's message.

"Stranger Things" co-star Noah Schnapp went one step further by sweetly promising to her "this year is gonna be your year. AGAIN."