(((weird artist)))
Did you see your doctor and get helpful answers? I hope so! Sorry that I am just now getting to your post, but wanted you to know that I care. Bipolar is a possibility that struck me. I nursed both of my children, and didn't experience any lows or hormonal changes until I stopped nursing. That's when moodiness and depression hit me pretty hard. Seeing as you are nursing, that's what makes me lean towards another cause being the culprit.
I hope that you've gotten some answers & relief to these up's and down's ~ very best wishes to you and your family!