It may seem like stress doesn't affect us or that we even have much of it in our lives, but that could be because it's so persistent in our daily lives that we hardly even notice it's there anymore. It's not until we take a good vacation (even a three day weekend away from work) that we realize how much stress we are under on a daily basis.
The pressure to make ends meet financially while maintaining something resembling a family life, and doing it all within the same living/workign space, is an entirely new kind of stress for most people that formerly only shopkeepers who lived above their store have had to deal with.
On a biological level, the stress response, especially chronic stress - the kind we don't seem to notice as much - has long term consequences such as the inability to lose weight, headaches, body aches, muscle aches, and getting sick more often.
Get a massage.
Watch TV, go to a movie, see a play, or do something else that you enjoy that you don't normally get to do.
Of course, the benefits of this kind of short term stress relief are also only short term. For longer term stress relief, try eating a healthier diet (which can be difficult to do under stress), exercise on a regular basis, assign work and home tasks to others where possible and take on fewer tasks where possible.
Those extra pounds might come off a little easier. You'll be in a better mood, which will cause people to react differently to you. You'll also start to get the physiological benefits.