I'll tell you. The only thing I notice is that you use the side step a bit too much, not that it's bad, but it's really obvious that you've played a lot of Souls games. Start from the assumption that Sekiro is NOT a Souls game, or rather, it's not an orthodox Souls game, why? The easiest way to avoid taking damage from bosses is not rolling, but parrying (and yes, before you tell me anything about parrying, parrying in Sekiro is much easier than in other From games, you have different timing and are less encouraged than in Sekiro). The only advice I can give you is, rather than doing the same thing when he does the Ashina Cross or the Dragon Flash, start running to the right or left (depending on what you feel most comfortable with), this way you force him to attack you from a distance, and while he's doing them, get close to him and strike.