She can't heal HERSELF, from her own mental trauma, especially when tuskyomi will knock her out... if the forhead seal can't do it, she can't do it... she'll enter a coma, like kakashiShe can heal others but not herself? Seems legit.
Ps- with itachi's speed, taijutsu skill and sharingan, he isn't getting hit.. he's enough of a genius to counter body path way derangement in seconds... tsunade can't win this, with or without mangekkyou