don't initiate with lash, but you were correct to chase and lash for the kill when he was gushing
macro your fam murder target, there's a lot of free dps you miss out without sticking your fam onto your target at all times. imagine if fam could autoassist you: that's the level of efficiency you should have with an easy-to-reach macro (I like F2-F5)
I would also use dispel magic to open with, necros don't melee hard so eating a free hit or two is no big deal. if you nail wraithform on your dispel magic that's a big dps increase for all your physical hitters.
for Kharrum's side:
it wasn't a fight you'd win unless you landed the sleep. good call on trying the sleep, but you should've managed to get 2 or 3 attempts before having to flee
