I can't tell if you're asking for champs to just help you through your plat series or champs to help you top lane in general, because you're not gonna get much success no matter who you pick if you don't take the time to learn them. But anyways...
Looks like you have a touch of experience playing malphite and gnar, both solid play-makers. Judging by your other champs, you seem to enjoy the type with the quick engage or zone control. Darius might be someone up your alley if you need a juggernaut, always good in teamfights if you can get in there. Poppy or Malphite are solid too for those engage tanks. Renekton or Irelia are good if you need a diver. That's the best I can think of off the top of my head.