I’ve been there and I know how exhausting it is. I ended up taking no pleasure in being with my kids because all I could of was getting then to bed so I could get on with all the housework and work work I had to do before I could go to bed. I feel I wished away years of their lives.
My advice is buy in help. I had a mother’s help who collected children from nursery and school, made tea for them and left out something for me. She supervised homework with the school aged child. She also did some housework and laundry and picked up a few items from the shops if required. I did a big food delivery online about every two weeks.
So none of this was fancy . The meals she cooked were basic and yes I had reheated lasagne / cottage pie with a bag of salad etc. the house was not immaculate but it was clean and tidy.
And it cost a bit . But I didn’t have to do much housework or shopping at the weekends or in the evenings.
I did this 4 days a week and stayed at work later Monday to Thursday so I could finish at lunchtime on Friday and pick up the kids myself . I had more time and energy to do things with the kids at the weekend ( Sadly they didn’t see their dad at all ).
I also had to have a conversation with my boss about their expectations that I worked every evening at home on top of my time in the office. I suspect that cost me a promotion but I hope that things are a bit different now post covid / flexible working.
None of this was ideal but it stopped be having a breakdown, which was probably the alternative.
I know this exact plan womt work for you @Cantdoothis as your child is in FT childcare. But maybe it will give you some ideas.
can I add - there’s nothing wrong with you for being exhausted. I bet there’s not a single man you know in your job who is doing what you are. All of them will have female partners who do most of all of this for them - the housework, childcare, wifework and mental load.
You are a star for just surviving this far ⭐️and yes you can do it , you CAN make this work .
and your ex is a shit. Just thought I’d add that , although I know it doesn’t help .