My advice to anyone struggling with starting iframes: get out before the swing comes. After you land a hit or two, make some distance before the enemy's attack comes in. I know this isn't always doable, but playing cautious at the start, then going more agressive later on, is a totally viable (and recommended) strat. Not every encounter has to be balls to the wall combat, with trying to dodge through hits. If you go for a heavier build, then you can probably block it and tank the damage, rather than take the full force for a failed roll. What I personally did, was learn to parry. I wouldn't recommend the parry strat to a new player though, as it can be hard to get a grasp on.
TL;DR Just back off whenever you can, or block the hit.