Fortify Your Sense of Self

You are probably much more interesting than you think. List your own attributes (all of them) and look at it from the perspective of a stranger to fall in love with yourself all over again.
Just who do you think you are? No, seriously - have you ever thought about it? Here's an interesting social experiment: for one entire day, ask everyone you run into, "What are you?". You'll get answers like "mother", "teacher", "Christian", "French", "surfer", "Democrat", "animal lover", "tired", etc. For one thing, you'll find out some intriguing things about people. For another, you'll see just how many ways we identify ourselves as individuals.
This is an important lesson, because your sense of self is what keeps you grounded and plays a role in determining how you react to life in general. It's also one of the very first things to get lost when we're stressed and overworked. Recovering your sense of self is an important step on the road to self-actualization, and a strong sense of self can ease many burdens. When you know (and are comfortable with) exactly who you are, you no longer feel pressured to overextend yourself.
Make a List
Start by making an actual, physical list of your own answers to our experimental question. Consider social roles, occupation, religion, ethnic background, nationality, hobbies, interests and anything else that defines you as a human being. Labels, if you will.
But just because something describes you doesn't mean it defines you. If you're working as a cashier to pay the bills until you find something better, don't list that, because it doesn't define you. If you're a cashier who loves her job and honestly can't imagine leaving the constant customer interaction behind, go ahead and list it - it's a genuine part of who you are.
Be Truthful
Not everything on your list must be flattering. If you're an alcoholic, put it down. If you're an irresponsible spender, put it down. If you're obese, put it down. Part of figuring out who you are is figuring out what you need to fix - not because other people don't like it, but because it could potentially cause you harm, and isn't adding any positive value to your life.
Consider the Indescribable
You probably have some characteristics that you simply cannot name, but only describe. Have you ever been watching a movie where the character does something vile or shallow or disgusting and you thought to yourself, "Ewww. I would never do that. I'm just not that kind of person" - that stuff counts too. So, your list could include things like, "would never pick someone up in a bar", "would never wear neon lipstick", "would totally share lottery winnings with the nice waitress" - you get the idea.
Take Some Time
Let your list rest for a little while. Come back to it every couple of days or so, giving yourself time to forget about it in between. You'll find yourself editing, adding and taking away, or making certain descriptions more succinct. It's not uncommon for these lists to be many pages long, and the journey to a completed list can be painful. You may find yourself questioning the worth of some people or practices in your life as your true self comes into clearer focus.
Use It
Once you feel your list is complete, start putting it to work. What is in your life that doesn't jibe with who you are? Would removing it from your life make you happier? Would it give you more time to add something else that will enrich your life? Of all the things stressing you out, which ones are you doing because you feel you "should", not because you honestly want to? Maybe it's time for some of these things to go.
To be honest, your list will never be 100% complete. People grow and change constantly - you are always evolving. You'll add to the list, take away, put some things back, but you'll always be focused on doing what's most important to you. In time, you won't need that list at all because you'll have an innate sense of who you are, with no complaints, no regrets, no apologies.