I had a worrier. He has gotten significantly better with age.
He still needs to ensure he eats and sleeps well to avoid the overtired hangry anxiety.
We sat/sit with our kids to go to sleep (eldest has now decided he’s good on his own at 10) so I’m not sure how helpful I’ll be but if I know it’s over tiredness talking I’ll do everything to encourage sleep ASAP. Sometimes that means not indulging the worries.
Smiling mind app is good. There’s free kids night time guided meditations you can play for them.
Writing out the worries does generally help my eldest but I save that for earlier in the day.
Sometimes I find bedtime needs to be brought forward to avoid that fatigue point. Or an evening supper before bed may help? Maybe the kids could have a supper while you and your partner have dinner then teeth and bed? Family meal times can be very restorative and connective for kids. Dunno just throwing ideas out there in case on is helpful.