Inability to downshift out of parenting mode at night

I will try to make this as brief as possible while getting all the data across. 45 year old male - divorced pretty traumatically two years ago (over the phone, when both of my children were with their mother) Previous trauma due to loss of mother when 18 Have really good co-parenting relationship with their mother now Financially stable, no impending doom I am recently engaged to frankly the most wonderful woman I have ever met The largest issue I am facing is the inability to downshift out of hypervigilance when the kids are with me, which is most effecting me at night. I have had bouts of acute insomnia over the years due to stressors (mostly work), but since the divorce it has been a struggle to no end. I was actually hospitalized over a year ago because I felt so hopeless before meeting my fiancé. When my daughter wakes up in the middle of the night, I get her back to sleep but then am unable to fall back asleep for several hours if at all. Then, the next night I get maybe 3 hours until I am wide awake trying to solve some problem, still being hypervigilant in parenting mode. Not interested in going on medication again (I am nearly off). I mediate and do deep breathing (not enough during the day), I try not to even try to sleep, but when I feel myself nodding off I jolt back awake. I am told this is because my fight or flight system is fighting my sleep pressure. Has anyone gone through this and how have they coped? I am in therapy, it definitely helps, but it's on me to practice things. This has truly been debilitating at times because it makes me sad to no end that my kids could stress me out this much without them even really doing anything (they are amazing kids, well behaved). thank you in advance!