Oh Quietly I feel for you...........and don't stop yourself having a cry as it will ease the tension. It's many years since my PFB went to Uni and I was in a terrible state - sitting in his bedroom crying and crying - DH said "anyone would think he'd died" but I just couldn't help it. And there were no mobiles then or FB. I think it did take him time to settle and I think he was a bit homesick but you know Christmas rolled round very quickly and then it was all so much better. Mind I wasn't much better with DS2 when he went - I couldn't even go with him and his dad to drop him off as I knew I'd be crying and embarrass him. I was less worried about him as he is more outgoing than DS1, and we used to visit him quite often, BUT I used to cry every time we left him, and for about 30 mins on the return journey home!!
Someone mentioned worrying about whether they were home safe, and that was a worry at first but I got over that surprisingly quickly. And now many years on, when I'm lying in bed at night still awake and hear boyish voices going past the house, I am so relieved that I'm not wondering if DSs are in the group and hoping to hear the voices stop outside our house and the sound of that key in the lock!
Just the way we're made I guess - I know lots of my friends had no such problems.