Women naturally have these mood swings due to their hormones. If your wife was ill, she would not be able to functon at work. When she is low, she needs you emotional support and when she is normal again, she can suceed on her own. It is good that you are not fighting anymore as that is the last thing she needs when she is low. Just be a loving, caring and understanding hasband when she is low and you will help her to recover much quicker.