One thing you are doing right is not extending overhead, I see a lot of people doing that, but stopping when your arms hit parallel is more of the classic RKC style. Here are some tips I can give based on the video:
- Keep your head neutral, don't look up the whole time
- Hike the bell further back, look up Dan John's "Bulgarian Goat Belly Swing" to get a good primer of the motion
- Stay TIGHT throughout the movement, you're looking, as my old RKC coach used to say "flaccid." The swing is a violent movement. Hike it back, load the hamstrings/glutes, immediately explode but then you have to brace your core to "catch" the bell and throw it back at the right time.
Check out some Youtube videos and try to find one by someone who is RKC certified to see the differences.