I know exactly what you mean. I do it, too.
The last month has been especially bad. First #3 terminates an almost 4 yr relationship with the young woman we 'thought' would be our DIL, then the passing of my StepDad.
I just feel like I've been runover by a Mack Truck. Keeping track of Mom, without appearing to be hovering has zapped my strength.
While Sarah has a beau (sort of) and your #3 doesn't like horses there is always hope for the two. LOL
Seriously, sorry about the split. Is your son all right?
I'm praying for comfort and tranquility in your life.