Hello and thanks for writing to us. My name is ***** ***** i'd like to help. I am sorry you are struggling with this inconsistency in your husband's mood. Most of us can relate that when someone's mood fluctuates like this, it is like walking on eggshells and extremely uncomfortable and frustrating. Have you ever talked about this with your husband? It can be really difficult to initiate these tough conversations but that is the best place to start if you have not, It is likely that if his mood is extremely unstable and unpredictable, he may also be suffering with an illness that could be benefited from treatment such as medications or counseling (or both).
At this point, the best thing for you to do is to gently point out to your husband that you are concerned about his moods because you would guess that it does not feel good to feel up one minute and down the next. Also, help him understand that this moodiness affects you and your marriage and that you would like to him to talk to a professional so you aren't constantly feeling unsure of which version of husband will be with you. If he is apprehensive, continue to engage in honest conversation about how this affects you and how much you care for him and your marriage. Offer to attend counseling with him and consider letting him select a counselor that he feels he might prefer as some added incentive for him to go.
If all this fails and your husband continues to decline help, deflects this issues, blames you, or becomes angry at the suggestion of help, then you may be in a tough spot. When it all boils down to, your husband's behavior is his own, including his handling of bad moods and his treatment of you. If he continues to choose to act this way and does not respect your feelings that his behavior is hurtful and ignores your pleads he get help, then you may face an uphill battle because he has to take the responsibility to want to make positive change. This doesn't mean it isn't worth supporting, encouraging and even trying to demand he talk to someone, but again, you can't control his instability or force he get help and without commitment and self-determination, people don't often make lasting change.
I hope this helps encourage you to continue to talk to your husband with a goal he get professional help. As you said, there was some illness in his mother which could be a factor here, so ideally, he should be assessed by a professional who may really be able to offer some opportunities for him to feel better and ore in control of his moods.
I look forward to hearing back from you,