I was Zed agaist Rene in top lane
Well, there's problem number 1. You were playing a squishy mid laner top lane and got reasonably wrecked by Renekton.
It doesn't matter how much HP you had, honestly; Renekton has the ability to dish out a ton of damage if you let him pull off his combo, and since he had you at half health while not taking much damage himself? He seized the opportunity, tower dove, and gave you a less-than-polite reminder that Zed is not a top laner.
WHATS WRONG WITH HIM? BROKEN PASSIVE, BROKEN Q, CANT DODGE ULT WHEN USED.. I was Kled agaist Garen in top lane
What's wrong with him? He's a beginner-level champion. His passive isn't broken, he hardly regenerates anything early on and without items. If you let him build two health items and Warmog's Armor, that's when his out-of-combat health regen gets ridiculous. And then, it's not his Passive.
And Decisive Strike isn't broken, either, it's just solid against most Champions. But, as Kled, you really shouldn't be afraid of a silence. You should have plenty of damage to chew through your opponents with Violent Tendencies, which isn't affected by Decisive Strike.
As for his ult...Eh. Honestly, I'm willing to bet he had a Black Cleaver over you, stripped you bare in that one second of Judgement, and you weren't careful enough to get out.
I was poppy agaist fiora in top lane
Much like with Renekton's case (although this time you were actually playing a valid top-laner), you played a bad matchup. Really, sort of a 40/60 match-up, since Steadfast Presence can block Fiora's Lunge, but, I still feel you chose the wrong champ.
Fiora's a middleweight - she starts off with a moderate amount of health and goes for damage first. Poppy is a Tank. Fiora breaks Tanks because of the %Health damage on her Duelist's Dance, and, as she doesn't have so much health to start off with, the 8% health taken away by Poppy's Hammer Shock can be laughed off.
So, the question here is, how many vitals did she hit when she issued her Grand Challenge? At 50% health, it should take about 3-4 Vital procs, even with Grand Challenge to finish you off. And if you let that happen, under your turret, then that's on you for letting her do it.
TL;DR
Renekton isn't OP, and Zed isn't a top laner
You got thrashed by a 5/2/0 Garen, that's really just your problem
Fiora kills tanks. Poppy is a tank. Know your match-ups.