As you may have guessed from an old post of mine, I am a proponent of dressing however the hell you like to make yourself feel better. I've employed this many a time: after job rejections, after a really long day, or just because I woke up in a bit of a funk. I dressed myself not for how I felt at that moment, but for how I wanted to feel. And, usually, it got better.
So here's my advice for what to do, and how to dress, when you're having a bad day.
First and foremost: wear what you love. Whether that is. It doesn't matter if it's the most comfortable pajamas you own or a beautiful gown. Find clothing that makes you feel whatever you need, whether you need comfort, beauty, happiness, or badassery. Wear it because you love it. Wear it because it feels right. Especially if your taste is more odd than your employer's dress code allows.
Remember, friends, that once you're off the clock it's your body and your time, and you can deal with stress however you like.
Go out or stay in. Do something that you enjoy, rather than wallowing in being upset or feeling off about anything. Do something that makes you feel better, whatever that "better" may be.
If you're up for retail therapy, go shopping. Go to your favorite store, a new antique store, or just go grocery shopping. Hold your head up high and do what you love.
Take a walk in the park. Enjoy a walk by a riverfront, through beautiful flower gardens, under green trees, or between shadowed tombstones. Enjoy yourself.
If you're not planning on going out, then find something to do that you enjoy within the confines of your own home. Watch a movie. Settle down in your lovely clothing, get a glass of wine, tea, or whatever suits you best, and enjoy being. Personally, I like a glass of iced chai in a black goblet from Target that makes me feel like Lucretia Borgia.
Finally, remember that you deserve to feel however you want to feel. The world may not help you in feeling the way that you want to feel, but your clothing can. You can be whoever you want to be, if only for a short while.
Find your own happiness.