If you can avoid dropping bf altogether, it's best to keep up a bit. I can understand feeling drained though!
I see two problems here - one is, you don't want to feed all day. Another is, you don't want to feed all night.
For stopping feeding all day, I have a fix! It's what I've done with my boys. Past a certain age, I only really feed them in bedrooms. So they can't demand feeds all the time - if they really want fed, they drag me to a bedroom. So if DS2 is poorly, he can have extra feeds, it's fine, but generally, we're always doing things, so it doesn't come up.
If you offer other drinks, they will drink them eventually. I wouldn't really bother with juice, there's no point to it - just give water and milk, and see if he likes it.
I'm not sure what to say about night feeds, I'm afraid I was mean and cut them out long before 18 months. You could go with CC, but that's a difficult choice for many ...