Maintaining Boundaries In A Marriage

I am struggling to follow through on boundaries. My husband has done many things in the last couple of years that I’ve never thought I would put up with. We have young children and I’m fearful of what life would look like if our family was broken up. When untrusting, distancing, repeated behaviour happens, what can my boundary be? Conversations happen and then the same cycle will begin again. Many would say to leave but i cannot stomach the thought of divorce.