The best way to lower your stress is to cast off your guilt as soon as possible. Adjusting your attitude will involve making some positive changes.
Locate the cause
There are many, many reasons why a person might feel guilty. Do you feel that you aren't doing enough for people around you or for yourself? Do you feel that your goals are unattainable? Separate what part of your guilt is realistic and what is internal. It may be that you're tricking yourself into believing you're selfish or lazy -- but when you account for how you spend your day, you'll find that's far from the truth.
Get a mantra
Mantras are simple phrases on which you can focus, meditate or pray. Find one you like that is true to who you are. Things like: I'm only one person. There are only 24 hours in a day. I always do my best and my best is good enough. Positive affirmation may feel silly at first, but setting aside the moment to strengthen your bond with yourself will pay off in the long run.
Toot your own horn
Compliment yourself once a day on all the good things you do. Maybe keep a journal by jotting down your most proud moment. Don't take things like carting your kids to school, paying your electric bill, and completing an important project at work for granted. Pat yourself on the back for a job well done.
Don't do a favor if the favor is never returned
There's a difference between practicing generosity and being a pushover. If there are people in your life who use and abuse your good nature, consider restructuring those relationships. Make them less about what you can do for each other and more about what you can do together. If you do want to help a friend in need, be sure up front that there is something good in it for you. It doesn't have to be compensation or a gift or even a dinner, it can just be a simple thank you or a nice note. If you don't get those things in return, don't be afraid to pipe up about it.
What's past is past
Though it's easier said than done, there's no point in feeling guilty about events in your history. Make amends to others and yourself for the wrongs of the past and brainstorm ways to improve relationships in the present and future.