I see your frustration pal, but Darius is only strong if you fight him on his terms. If he pools you in and you try to fight him, you will probably lose. If you engage first. most definitely you can win the trade.
He has to stack his 5 stacks of passive. It seem quite easy to achieve in lane against one enemy, but when it comes to teamfights, people start to kite him. You get a couple of stacks on every champion but ultimately you can't build all five of those stacks.
It is not so much about who counters who, it is more about a proper engage and all in. Also ganks play an important part.
Overall, Darius is hela strong in lane and constantly tries to pull you in. Watch him, wait until he uses his E or W on minions, then you can engage and all in him. Make sure you're using Good Runes and building appropriate items.
Like people here mentioned, Darius just like Renecton, falls off quite a bit in late game. Unfortunately most of the games end at around 20-25 min mark.
Actually I can outduel him with master Yi right from level one, and he can never equal me later on. But if he pulls me in, instead of me going in first, I almost certainly die.