As someone who meanders between diabetic and prediabetic and who has struggled with mood disorders for most of her life, absolutely! Blood sugar and brain chemistry issues are intimately related. Keep tuna or peanut butter or cheese or some kind of easy protein on hand, and try to reduce your carb intake to 180 grams a day. Eat fresh veggies where you can; I eat a lot of salads and celery. Also, if you can, get some vitamin D3, about 2000 mg/day is what my doctor prescribed. (I'm tall and sturdy.) I take an anti-depressant regularly, but the dietary changes and controlling my blood sugar have made almost as much if not more difference to my mental stability.

Your mother...gah. She sounds like mine. They're so psychically destructive, and then they wonder why we are, well, destroyed. Go figure!