It's important to take care of ourselves and take care of our family. If we are unhappy, they may be unhappy and if they are children involved, you are showing them what it is like to be in a relationship. This may become the norm for them.
Divorce can easily follow a situation like this and the problem is that divorce can take a huge toll on the family. Even after the divorce has been finalized there may be financial issues, co-parenting issues, etc.
So what do you do...
I will tell you the worst thing you can do is nothing and let things stay the way they are. You need to get out of the negative cycle you are in and that means changing habits in the family.
The way to change habits is to first become aware of what is at the root cause of the issue. Once you are aware of the root cause then you can move ahead to improve the root issue. This is an extremely difficult thing to do, even with support and help. However, once you do this, you will be on a better path and you will see immediate improvement in your relationship.