Everyone has given you great advice. I don't know that I can add much, but I'll tell you about how I deal.
I have a really stressful job, and emotional eating (and drinking) is a daily challenge for me. My go-to solution is yoga. When I REALLY want a gulp down a bottle of wine, or chow down a giant cupcake after a bad day, I make myself go home, pour a big glass of water, and head down to my basement for a date with Rodney Yee. (Yoga guy)
Afterward, I always feel better. Sometimes I still eat the cupcake. Sometimes I still drink the wine. But after practicing the yoga, if I choose to still eat the cupcake, I know that I CHOSE to eat it - I wasn't doing it to avoid dealing with the stress.
Be kind to yourself. Every day won't be like this one, and tomorrow when you look back and see how deftly you handled this bad situation, you will be even more proud of yourself.
Injustice anywhere is a threat to justice everywhere.
-Dr. Martin Luther King Jr.