Tanks, juggernauts and more

So I’m having this struggle, I play panth top and since I’ve otp’d him I’ve gone from silver to platinum 2 with 60% win rate after years of not playing league, so obviously I’m quite happy with him. The issue is, I find getting a lead is really easy, I roam, get kills and make muy team get fed but, against certain champions I feel y can never contest a sidelane. Specially tanks that for some reason just deal so much damage while taking none (ksante, malphite, mundo) Is there Any way apart from BC to deal with them? Also id like to address zaheen, ik he’s been nerfed and all but, how is it fair that with a gold and item lead I have to gather the fellowship of the ring to even try to deal with him? He’s like a raid boss with 2/3 items while I’m closer to a sardine with 3/4, maybe it’s skill issue but I feel panth needs some sort of tuning to be more bruiser-ish per se. Build was: Voltaic, BC, Shojin, Chempunk, Tabis if I’m not wrong, any tip is welcome 😁