I'm another one who thinks it's a good thing that DS told you what's been bothering him, mothercat. And it's good to know it wasn't about money either. I'm sorry that he felt abandoned when you went back to school/work, but I know that wasn't your intention and, IMO, it's good that it's out in the open.
Kudos to you for not trying to defend yourself! I know that must be hard. But it would only have led to arguing, etc. The important thing is that now he felt "heard."
I'm also glad there is no concrete reason for him to fear that you would break plans w/ your new GC, etc. Please make sure that, in the near future, you plan any dates w/ DS and family carefully, so you don't have to change plans, etc, you know, just not to give DS any ammunition or whatever the correct word would be.
Enjoy your new grandbaby!
To think that London, or anywhere else for that matter, does not belong to any one demographic
A Good Year Film4 6.40 tonight
Recommendations please, for a stopover on the way to Loch Tay