I cried a lot before DS PFB went to Uni, cried on way home after we dropped him off and for about 48 hours afterwards I felt sad and like part of me was missing.
But it was actually much easier than I thought after that.
Think of all the positives the tidy bedroom, less washing, ironing and cleaning is easier, the bathroom is less busy and less washing up, cooking and constantly buying food and snacks and reminding him about every mortal thing.
I would agree try and encourage them to stay at Uni and not visit for the first three or four weeks if poss to encourage friendships and get the hang of washing and cooking and filling time when they are bored getting used to their Uni city and new friends etc.
DS phones or face-times us usually a couple of times a week most weeks. Sometimes less and sometimes he replies to texts but often ignores them.
DS is very happy at Uni and has had a good first year which helps us adjust knowing he is so happy. When prompted sometimes he sends occasional photos no doubt carefully selected (which is also really nice).
As said above tell them you love them, care about them, haven’t forgotten them and are always at the end of the phone. Send maybe a couple of texts a week or photos of the dog if you have one which goes down well but otherwise you have to be guided by them.
We got through the first year which this time last year I doubted whether I would.