If my sugars are running high or are generally unstable then yes, I feel quite down in the dumps. Mainly as I feel unwell and have a general lack of energy. It's not so much about avoiding certain foods, more about making sure your levels remain at the right levels. I'm type 1, so I do this by injecting and by controlling what I eat.
You might benefit from following a low carb diet. This will help with your sugars levels. It can also help you to lose weight.
I find that startchy or processed goods leave me feeling really tired, so I try to avoid them. I also feel a lot better, physically and mentally, if I up my I take of fresh fruits and veg.