"Later" should be understood in reference to "after the 4 PM bell". The boss has invited him to have a drink at a specific time; Jerry's dinner date with his wife occurs long enough after that point that he believes the drink with his boss will be over in time for him to make the date.
It might be clearer if we substitute a more specific time in place of "a bit later":
He had a dinner date planned... but that was not until 7 PM.
If you have a date planned for 7 PM, it's safe to assume that a 4 PM drink will not make you late.
People here often grumble when a questioner hasn't done enough work on their own before asking us to help. But in your case I think you've done too much!!
Bronte is doing something unusual here. Imagine you've been looking after a neighbour's child all morning and he has been driving you mad. When telling a friend about it later you might imitate the child's whine and say, "Why haven't you got any Coke? Why can't I go to Dweezil's house? When will Mum (Mom) be home?" Or you could put on exactly the same voice and say, "He wanted some Coke. He wanted to go to Dweezil's. When would his mum be home?" Have you heard that being done? It is a bit illogical: the child didn't actually say the words "He wanted" or "his mom". Nonetheless, I've certainly heard myself doing it.
So. The aunt didn't actually say "She regretted..." Bronte uses the speech marks (inverted commas) in such an unorthodox way because she wants the reader to imagine her aunt's voice.
What her aunt actually says is something like this: (You're probably way ahead of me and don't need the rest, but I'll do it anyway!)
"I regret being under the necessity of keeping you at a distance; but until I hear from Bessie, and can discover by my own observation, that your are endeavouring in good earnest to acquire a more sociable and childlike disposition, a more attractive and sprightly manner-- something lighter, franker, more natural, as it were--I really must exclude you from privileges intended only for contented, happy, little children."
A couple of things you queried:
to be under the necessity of: needing to or having to
endeavouring in good earnest: trying seriously
from privileges intended only for contented, happy, little children:
not "from things that only kids enjoy" but from things only children who act like children - proper children, in her view - deserve.
The aunt sounds pretty loathsome. As you say, she and Jane clearly dislike each other. I should read it.
Best Answer
The sentence is describing how the people are "caught" in a loop that they cannot get out of.
essentially says:
Then:
essentially means:
Ergo, they are stuck.
It's worth noting that unconscious in this context means "unaware of their miserable existence, as if in a stupor." It doesn't mean the people have fainted or passed out.
NOAD defines it as: