I think you should find another top laner for the Jayce matchup specifically, if you are having that much trouble with him. I don't think Jayce is particularly strong outside of his poke. He is an easily gankable target since he shoves waves a lot. I also don't think he scales very well in comparison to other top laners, he brings a lot less to team fights. Darius plays an early aggression game and you can't play that why against a Jayce.
You may want to try out
against him. Jax outscales Jayce, can gap close, stun, and block auto-attacks. The problem is you would be very vulnerable early and would just need to farm, but once you kill him in lane he will no longer be a problem for you unless he gets help.
I don't know what style you like to play though in top lane. I play a very passive farming style and prefer champions that scale into the mid or late game. I don't play aggressive champions in the top lane.