I started to play the game as Sebille as a Shadowblade. What I found was that the available finesse weapons, daggers, do very little base damage, which means that even if she's backstabbing the damage that is multiplied up is still very little damage. This means I'm finding the early fights quite difficult with this build.

What am I missing? Should I change the starting build? I've seen some build advice online but it all assumes that I've already reached a much higher level.
Also: are there easy ways at low level to get backstab damage without using the backflip move and without spending all my AP on moving about?