Spinach is full of many necessary vitamins and minerals. That it made such a substantial difference likely indicates your diet led to some nutritional deficiencies. You might wish to consider a more balanced diet, or use more comprehensive multi-vitamin/mineral supplements, such as those from Twinlabs which I mentioned in an earlier post in this thread.

Almonds, walnuts, and cashews are a bit more heathly than peanuts (which are not nuts, but legumes).

A low carb diet places more stress on the kidneys. This has something to do with the process which breaks proteins down into usable energy. Higher levels of amonia are excreted in sweat when that process is taking place.

The ketosis from a low carb diet can be useful for weight loss, and has been shown to improve mood and stability in some people with bipolar, but as a lifestyle change it can become physically unsustainable.