I get it. It's flipping hard work being the one having to do the 24/7 weeks and weekends, the appointments, the cooking, the shopping, the cleaning up after them, parents evenings, the school runs, the clubs, the illnesses, the emotional upsets and the rest
XH gave up on his kids when he left. DD never sees him now, as he's disappointed her too many times. DS does, as he feels obligated.
They're nearly adults. They know I'm the one who's always there for them. Whilst I wouldn't have it any other way, I'm sad that they've missed out on having the dad experiences and guidance that they should have had growing up. Instead they were made to feel less important by him, as once he left, everything was all about him and his needs and wants. They had to bend to him if they wanted to see him rather than him pursue them to make up for what he'd stolen from them.
The way I dealt with my anger towards him about this is to realise it's ok to be angry, as he hurt my children. I will never stop being cross with him about this until the day I die. I'd have loved weekends and holidays to myself, but I love my kids more than life. I channelled my anger into loving them fiercely and constantly showing them how they were my priority and first thought. One of their parents needed too.
Years on, I still occasionally get ranty angry to a friend about him when he does something particularly selfish that again affects the kids. On 2 occasions this year I've had to see my children's faces sink when they read a text from him that lets them down. Makes my blood boil every time.
Whilst I've let go of the anger I feel because of his behaviour towards me, I don't think I'll ever move past the anger I feel when I think about the effect his absence in their lives had on his children. Maybe you won't either.