Hey sunny, how old is your DS? My DS is 4.5 and I'm approx 11 weeks. I was utterly zombified from the TWW until about a week ago. Such terrible trouble getting to and staying asleep.
My experience with insomnia is that quite often it's a self-fulfilling prophecy - if you're worried you're not going to get any sleep, you're probably not going to get any sleep.
DS is in school and I work everyday, so it hasn't been easy, even with OH around to help with some of the school runs.
The way I managed to get through it was to get ready for bed at the same time as DS. Have dinner with him, have a bath with him, get in PJs at the same time, then force myself NOT to do anything after his bedtime. It's hard, I know because that's usually when you have time for housework. I just did the very basics after work and the bigger stuff at the weekend.
When it got really bad, I would snuggle up with DS and let him watch an hour of TV whilst I shut my eyes. Again, not ideal but it gave him a bit of unwinding time after school, and gave me a bit more energy in the evening.
If I couldn't get to sleep at night, I would just go downstairs and put something easy to watch on the laptop (because it has a blue light filter), knowing that even though I wasn't sleeping, I was still letting my brain and body relax. This allowed me not to stress over insomnia, and quite often I would end up drifting off eventually.
We deliberately waited for DS to be a bit older before TTC #2, and it's paying off already. He's gained so much independence since starting school and able to do more and more by himself. This really helped when I was struggling with lack of sleep.
I hope you can find a way that works for you OP. I really empathise with those with insomnia. Whether it's short or long term 