Talk It Out
We tend to "bottle up our feelings". Confide your worries to some mature, prudent person you can trust. The "talking out" process has enormous value.
Work Off Your Anger
Let revenge wait for another day. It eats away at its possessor. Work off your pent-up energy by cleaning house, working at a hobby, taking a long walk or just doing anything you enjoy. It takes a calm head to handle a challenge in life properly.
Talk One Thing at a Time
Do what is most expedient. Start with the most urgent; forget the rest until you get to them. Just remember the story about the man who could not break a bundle of sticks - until he took apart the bundle and broke them one at a time.
Escape for a While
Sometimes - if you are able - get away for a while. A change of activity, or scenery, or people helps provide some variety in your life. Getting away if only for a day is still a great boost to your attitude.
Go Easy on Yourself
Put an honest effort into the things you do. Be tolerant of your shortcomings. Nobody is an expert at everything. Nobody was given all the gifts. Be nice to yourself - you deserve it!