First – you should know that you are not alone.
Second – in your dark moments, try to ask yourself whether you really cannot do it anymore or you are:
– simply frustrated.
Frustration is a big one. I know the feeling ….
Get help if you feel that you are really loosing control.
If you feel old and fat and whatever – try to do something about it!
Difficult as it is, start a diet, start exercising.
JUST DO NOT GIVE UP!