Yeah, you're not leaning over enough. But also, your upper back is soft so if you were to lean over, the bar is likely moving on you.
Get your chest up before each rep, then send your ass back as you start and you should be able to stay midfoot. Then drive the hips out of the bottom while you keep your nipples pointed downward.
Also, narrow your stance a bit so the heels are under the shoulders and invest in a pair of lifting shoes.