@ShalomJackie They get so overhwelmed by choices and decisions at this age. FWIW, here's what I do:
I try to have a couple of hours each week to go for a walk or lunch with DC to discuss uni choices and courses. DS wants to apply to Oxbridge and he gets a bit snappy when we discuss the extra work that entails. But I've said to him, it's his choice. If he wants to go for it, he has to understand how much work he has to do to be in with a chance. And if he doesn't want that extra work, that's a completely valid choice. He can do brilliantly, with less pressure, applying elsewhere.
I think it's hard for us and them, to get the balance right between pressurising and encouraging, between being honest about what their goals entail and overloading them. The only thing I keep saying is that anyone who applies for Oxbridge must accept that not getting in is no reflection on their intelligence, and if rejection would smash their confidence, then they shouldn't apply. It's something of a lottery.
I also say it's a lot of extra work which I won't nag about but will help organise if he asks. Again, if that extra work panics him, I think he's better off aiming for a uni where he feels he'd fit comfortably, working at a steady, unpressured pace. Deciding to aim for Oxbridge is a big step up and this is the term where that hits home.