I dont use beastial wrath either in my build
Assuming rest is maxed that leaves 5 spare points for stats and diseased claws. I'd wager you'd do better with Ooze over stats anyday.
@Arik we can't really help as we can't see the battle so really there's only 3 things to explain why you're losing:
Sedna player is just better then you.
You're equal but you just make one more mistake then the other person
You simply can't win alone in the situation.
Leaning towards the 3rd as it's the most common one when facing sedna.