What ends up happening is the make you push. If you sit under turret, you're 0/3 already, they don't care and they'll dive you. If not, they'll freeze and stave you your cs, as entering the frozen "area" will get you killed. The only solution to this is to get your jgler to help, but they won't "Because helping lanes that are behind is pointless".
In a Darius v. Pantheon match, you will have to use Q to farm, and it's ridiculous, because that pushes the lane to Panth's tower, so he freezes it there, and you're vulnerable to ganks or getting all-in'd by Pantheon. And at this point, you can't roam, because you're 0/3 and can't do anything to anyone.
If you're pushed to turret, and the Panth is roaming, you push to punish him for roaming. If you just freeze it in front of your turret, prepared to get ping spammed by everyone else asking you to push.
When I get dived, I don't just sit there, half the times you have to make some offensive action because that's how a champ's kit works. Going back to Darius again, you need to pull them closer, as that procs CoTC, and slows them slightly. You have to turn around and trade with AA+W, or try to land double Q procs.
For Darius vs Pantheon, he just WEQs onto you and you can't do sht about it. Don't say" just don't trade and back off" because that would lose you the lane even more.