well for starters janna have a low win rate of 65% so basically u will win 65% of ur games if u are decent with her. and u are buildwing wrong items aswell
Nothing u have there benefits people lategame i mean u have varus AND olaf and no zekes herald
kages lucky pick? worst item
anyways, It also depends on what elo you are. If you are 0 - 1400 you sure as hell shouldnt play support. But anything above that is carryable with support janna. Just follow ur ad/jungler and always try to fuck up enemy blue early on by just going in attacking etc (they cant catch u cuz u jannaaaaaaaaa)