first of all I'll admit that I'm not a coach, just a dad- but when my son has had similar struggles, it's because he was waiting too long to load- then trying to catch up quickly. looking at your film, that may be a possibility. The way he addresses it is to start loading hands and upper body earlier- a cue would be to start as the pitcher's knee reaches the top of the windup- then slowly coil, and then release to swing. the audible cue his coach uses is, as funny as this sounds "kapow" It should be a "Kaaaaaapow" not a "kapow". gradual load/or coil, then a quick release.
don't know if this helps or not- but there it is. I hope that nothing I have said will be held against me if it doesn't work!