Trouble Getting Hips Up in Inversion

[JackBetbeze]

Hey guys,
So I've got an issue in my inversion where when I invert I tend to point my feet straight up but then expand outward towards the end of the pit. After watching myself on video I figured it was because I'm not pulling my hips up. It also looks like I'm not sending my head back. After some research I've found that it looks like my butt is "in the bucket" and not being brought up to my top hand.

Honestly this is all self speculation. I don't even have a coach, I just have a really good fellow HS vaulter teaching me lol. Is my hips failing to get up my issue here? If so, how can I fix this? And are there any other things hindering me from getting a better inversion?

Here's a video of me vaulting:
https://www.youtube.com/watch?v=MXMQKCs5vQ8

Give it a look and let me know if there's anything I can do to get better!