Rav Yisroel Salanter, the founder of the Mussar movement, tried to change the world. When he realized he couldn’t he focused on his community. When he realized that wouldn’t work, he focused on his family. When that didn’t work, he came to the conclusion that all he could do was change himself. Therefore, the only thing you can do (assuming that your husband will not go for professional help with you) is to work on your countermoves. If you are very respectful and positive with him, he will feel uncomfortable being negative. It may be that he is critical of you since he may struggle with low self-esteem. Sometimes we put people down to feel better about ourselves. If this is what is going on with your husband, then by building his self-esteem, you will help him be more positive.
In any event, a positive approach will hopefully help you with this situation. In addition, it may be helpful for you to get some extra help in the house. That will go a long way to making you feel more able to deal with things.
If your husband agrees to go for therapy – wonderful. But if not, you may want to seek professional help to build your self-esteem and help you be strong. I wish you hatzlocha in this challenging situation.