No, you shouldn’t break up the family over this — at least not yet. The most important thing you said in the letter is that your husband has changed in a major way. What you should do is insist that he get a complete medical workup. Sometimes medical issues can mimic depression. If he is medically fine, then I would strongly encourage him to see a counselor for an evaluation for depression. His behavior is way beyond grumpy. His job may be getting to him far more than even he understands.
I hope the two of you can get on the same team to solve the problem rather than on different teams fighting with each other. You’ve had a good marriage and you have a child together. It’s worth making the effort to try to regain what you had. If your husband refuses to work on it or if it turns out he has a secret that makes it impossible for you to be with him, then you will have some hard decisions to make.
I wish you well.