What do if husband yells and criticizes every small detail when discussing serious matters?
This is a difficult situation when you and your partner have different viewpoints or expectations about the relationship and/or parenting/household responsibilities. It also sounds as though he may expect perfection or control over how things are done. Does he know and agree with your expectations from him? When a relationship feels unbalanced, or one person feels as though they are never able to satisfy their partner, despite their best efforts, this leads to feeling rejected and despair.
One conflict resolution approach is to focus on what you are able to change and control, and communicate those things to him. Do you have concerns about how this is impacting your children? Sometimes when two people experience difficulty with communication, changing the focus to the children's needs being met or expectations you both agree on for the children can be helpful and avoid pointing fingers at what the adults do/don't do. If you are able to identify the goals and expectations you both have for your children, then you can problem solve the other things both people need to do to make that happen.
It sounds as though having a non-biased person to represent and help you both discuss your feelings and concerns would be the best option. Does he know you are looking for help and is he willing to seek help? For one person to pursue change, but the other not to or not develop a clear understanding of your needs and feelings, it creates more resentment for you and limited progress. If you communicate with your partner the things you have tried to do on your own, as well as that both of you are a part in creating a supportive and positive relationship, this would be the next step to resolve and move forward. A relationship takes understanding and flexibility, and if you are both frustrated, that can be a starting place.
Look at your current supports and the positive aspects in place for your family. Are these tensions leading to difficulties for you or him in other areas of your life? If yes, that is another indicator that seeking help together would be a helpful next step.