I stole my coworkers lunch

I’m so ashamed of this and don’t know why I did it. I’m not hungry at work I always eat when I get home. But everyday at lunch this one lady in our office brings these huge containers of food. Seriously it’s enough for 3 people to eat sometimes. She always leaves it on the bottom shelf of the fridge uncovered with her name on it and walks away from lunch early to get back to work. I was sitting there waiting for my ride to come pick me up when I noticed her lunch sitting on the bottom shelf and just did it I grabbed it and put it in my bag and took a picture of it on the bottom shelf to pretend I was just texting. So if she noticed it missing she’d see the picture of it in the fridge. Then I got up and left to wait outside. I felt terrible and guilty and like I was a horrible person. I have never done anything like that before I’m not a thief I don’t steal. I don’t even know what came over me to do that. I was so ashamed I didn’t even tell my husband I told him I brought it for lunch and was just eating it and he looked at me weird because he knows me eating at work is weird for me. But yeah now I just feel bad and guilty. I may stop eating at the company cafeteria now because I don’t want to be near her knowing what I did.