Keep a journal. Write down your thoughts, fears and anxieties. The process of writing is therapeutic, plus it can help you clarify what you really need. Buy yourself fresh flowers. Spend time outdoors.
Sunlight can be a mood-lifter.
For the winter, invest in a full-spectrum light bulb, which imitates the sun's spectrum and can make you feel better indoors. Go to a pond and feed the ducks. Use an answering machine to screen calls and don't feel compelled to return every one. We'll do our best to call back before the baby goes to college. This is a funny, but clear, way to let people know you can't get back to them right away.