All I can offer is - the more you put your energy and focus into getting informed, recording your food, your levels etc etc...the more you will be in control. I am of the opinion that, while there are obviously many causes of depression and anxiety, not being in control or fearing that we have little or not control is not far from the heart of the matter. So - get in control of what you can.
I am also utterly certain that we are all variations along a curve of mental health, as we are with physical health... but I would also suggest that being temporarily overwhelmed to varying degrees by things - even to the point of anger or depression - is to be human in the modern world); pardon the expression but only a total nutter could possibly find it all wonderful! Good luck.