Back is definitely significantly rounded. Doesn't look like you ever get it set properly to begin with. It needs to be set hard and tight. Do you follow Rips steps made simple? deadlift technique - Follow that link and pay extra careful attention to the end of step #1 and step #4 as they for sure apply to you.
Bar path is also all over the place. Might not be directly over mid foot at setup. You need to pull it in contact with your shins the entire time (sweats may help) and break from the top with your hips first before bending your knees so that you don't bring the bar out and around.
I'm not a coach by any stretch, but if I was you I would do a significant deload to work on these things.