This falls directly into...
...the you can't take care of others until you are caring for yourself bucket. I've also heard it phrased as, put on your emergency mask before putting one on others.
When you can do so freely, and without hurting yourself and your children, then help other people if you want.
But, when what you have is the need to focus on you and your children and don't have the energy and ability to spread yourself thinner, then others are going to have to take care of things for themselves, like it or not. As somebody else here said recently, when people pleasers stop people pleasing, people are not pleased.
Often people label those caring for themselves as selfish, and often they childishly or ignorantly lash out at us. God bless them but f' them. You have yourself and your children to care for, and that's exactly what is most important.
Adults are responsible for taking care of themselves, children are not. That means the only people you are responsible for besides yourself is your kids. That's it. Nobody else. Just you and your kids.
Take care, and take what you want and leave the rest,
Cyranoak