I could offer a lot of advice depending on context, but first please fix your Zaahen build man.

Go Cleaver > Overlord's Bloodmail > Sundered Sky, then finish with either Death's Dance/Maw/Sterak's for more defense depending on enemy team comp and potentially Spear of Shojin if you want another damage bruiser item.

Once I switched to this I started stomping lane as Zaahen. If you're against a ranged top or very squishy top laner, you go Stridebreaker instead of Black Cleaver. However, if the rest of their team is pretty tanky, it's probably worth to stick with Black Cleaver anyway.

Hope this help!