Humankind is weak

Stress at work makes me starve myself all day. I had a worker tell me they need off all weekend and I have no one to work in their place so I will be doing tripple the work I usually do now. I didn't eat anything all day and then when I came upstairs I ate a big meal and now I am going to bed. It is had for me to change my lifestyle. How do I make the right decisions when accessibility to junk is so much easier?