No three year old baby is capable of giving emotional support to a grown up. They barely if at all understand it and your husband should not be leaning on a baby for support.

A three year old can seem much more capable than they actually are, at that age they are still very much just a baby. What a baby wants most is to feel loved and SAFE to explore and learn about themselves and the world around them.

I understand you have been trying to learn and get support. Most people prefer to gather information and make up their own mind about their relationships. Remember, at three years old a child has feelings they do not understand. Avoiding comes from a child not wanting to feel uncomfortable feelings they simply do not understand.