It's eye-opening how many of our dcs (and how many of their mums) have had very similar wobbles. Best of wishes to all those who are going through it. 
I wonder how many of our dcs recognise that there are others dealing with the same problems as them. They don't really know each other yet and I guess they're all outwardly acting the friendly, social person a little. I bet it feels like everybody else in their uni is having a fantastic time with no hint of homesickness or anxiety and they feel as if they're the only ones who are going back to their rooms and having a quiet crisis. I bet 90% of the smiles they see are actually masks that slip a bit in private (or on the phone to mum).
Decorhate - yes I think we are in the same place
. DS has seemed happier with his course this week. They were doing new stuff which he found interesting rather than re hashing A level and he likes his tutor. (Mind you, we've had minimal contact so I'm trying to read between the lines of his texts.)
Ds was so adamant that he wouldn't be homesick or want to come home before going that I think he feels like he can't admit to missing us, but he did say a bit plaintively When are you going to come and see me? so we're planning to go next week and take him out for a meal.