When you are angry or frustrated, what comes out?
Whatever it is, it's a good indication of what you're made of.
- H. Jackson Brown, Jr.

Consult not your fears but your hopes and your dreams.
Think not about your frustrations,
but about your unfulfilled potential.
Concern yourself not with what you tried and failed in,
but with what it is still possible for you to do.
- Pope John XXIII

Our frustration is greater when we have much and want more
than when we have nothing and want some.
We are less dissatisfied when we lack many things than
when we seem to lack but one thing.
- Eric Hoffer

If you get frustrated by some of your family,
focus on the good aspects of your relationship
and attempt to overlook the irritations.
Then give thanks for everyone who plays a part in your life.
- Jonathan Lockwood Huie

My recipe for dealing with anger and frustration:
set the kitchen timer for twenty minutes,
cry, rant, and rave, and at the sound of the bell,
simmer down and go about business as usual.
- Phyllis Diller

All that is necessary to break the spell of inertia and frustration is this:
Act as if it were impossible to fail.
That is the talisman, the formula, the command of right
about face which turns us from failure to success.
- Dorthea Brande

Redirect the substantial energy of your frustration
and turn it into positive,
effective, unstoppable determination.
- Ralph Marston

Further reading: How to be Positive Around Negative People

How to Move On and Let Go

When You Feel Sad for No Apparent Reason

How to Think Positive