Sorry to hear about DC feeling lonely and sad. It's so difficult to try and help them feel better from a distance.
Letting them know that they're not alone, and that many others will be feeling the same as them might help.
I think my DD1 would have struggled last year if she hadn't joined a club very early on which kept her busy and gave her an instant group to belong to.
There will be new clubs and societies starting up all the time - they really are a good way to meet kindred spirits.
It's still early days for them.
The recent break ups obviously aren't helping, it must be very hard.
My DD2 has ended things this week with her boyfriend of 2 and a half years. Im heartbroken for her, but part of me is relieved it's happened this side of Christmas to give her chance to get over things before her Alevel exams and the whole uni thing.