Ok have been staring at these two for too long!
19a Turns and stumbles losing head ---E-S
17d Holding a sharp knife ---A-E-
Please put me out of my misery!
19a i think is "ALTERS" (stumbles losing head = (f)alters)
17d i am less confident about, but believe is "CLEAVER" (cleaver being both the sharp thing and/or the person who holds the sharp thing)
any further input/confirmation wlecomed!!