Not bad for your first big room song. Big room is my favorite genre, and I enjoy making it. Though for me it can be very difficult to make. That's because only 1 / 5 of my big room ideas ever make it to a full song. I would recommend on watching a tutorial on big room style. Most big room songs have the same structure: Intro, Pluck Melody, Trance (sort of) lift, Build up, Drop, and then repeat, but without the intro. I'll send you a Big Room sample pack that I use. I would recommend watching some of Panos Savvidis' tutorials. They helped me a lot. One big thing you're forgetting is the sub bass in the drop. That's what make the drops light up!
Tutorials:
https://www.youtube.com/watch?v=qBX7gbBAooo
https://www.youtube.com/watch?v=lvhPso9AvXM
https://www.youtube.com/watch?v=tRTH31CJGHk
https://www.youtube.com/watch?v=hYNe4thHhzw
https://www.youtube.com/watch?v=G95A9qQu6U0
Big Room song examples: (Besides mine)
https://www.youtube.com/watch?v=CM2pIelrItM
https://www.youtube.com/watch?v=VctDhcMzbJ8
https://www.youtube.com/watch?v=AYDrFbfu35g