The 19-year-old, who starred alongside his girlfriend in the CBBC series So Awkward, was found dead at his London home last week.
Sharing a candid shot of Archie lying on a bed and pointing a camera at her, Nethra wrote: “There was once a boy named Archie Lyndhurst and he made me the happiest girl in the whole world. A boy in a white beanie with his skateboard passed two wooden doors with an unimaginable thirst for life in the hallway of Sylvia Young Drama School. He was sitting across from me as my head was buried in a script, trying to book a job. He was there for his friend who was really nervous and auditioning too, he was always there for his friends.
“Blissfully oblivious, I had no idea my future was sitting right in front of me. ”
She added, “My boyfriend isn’t doing her justice. Archie, you were my person and my best friend all in one. Spending the rest of my life laughing and having adventures with you was just right for me. Everything made sense with you. You made me laugh like no one else and you loved me in such a way that I will be forever grateful.
“Being loved by you was a bonus, but I can say with pride that you are the most amazing person I have ever met and have had the pleasure of being in love. The world is not ready for what is yet to come. beautiful soul, thank you for a life i will never forget.
“You have my heart forever. Thanks for loving me. Thank you for making me the luckiest girl in the world.
“Every day with you has been the best day of my life because I finally met my match.
” I love you. Forever and always, your tiny X dancer ”
Her supporters rushed to support her.
“Sending all my love,” one commented.
While another posted: “So sorry …”
The circumstances of Archie’s death on September 22 are not yet known, but are believed to be “not suspect.”