I read a good quote today: "Worry is thinking that God won't get it right.  And bitterness is thinking God got it wrong."  Been there, done both.  It doesn't work very well in either case.  You have to live a few years to realize that God will get it right.  He never gets it wrong.  We just can't see the big picture.  Sometimes you are just one small piece of His plan.  And if that part is suffering, just know that it is not for nothing.  God honors us by including us in His complete plan.

I like the scripture, "In everything give thanks, for this is the will of God, in Christ Jesus, concerning you."  It doesn't say to give thanks for what is happening to you when it is a difficult thing, it says to be thankful "in" everything.  There is always something to be thankful for "in" your present situation.  The scripture says, "...in everything give thanks...".  It doesn't say, "...for everything give thanks."  I don't like the bad, uncomfortable, difficult things that have happened to me.  God is not requiring for me to like those things.  Just endure.  Stick it out.

When I am discouraged, and find myself unable to find solutions for my circumstances, I try to get through what I am frustrated about by thinking on the positive things that are going on in my life.  I can always find a zillion things to be thankful for.  And thanking God for those things lifts my spirit.
"...whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue and if there be any praise, think on these things."  Philippians 4:8

Paul got it right in that verse.  What we think about is a direct contributor to our attitude.  If you are thinking about things you are thankful for, if you have a thankful heart, you will be a much happier person.  If you dwell on what's going wrong, what's bad, what's difficult--you'll be despondent, discouraged, and a grouch.

There always seems to be something going on in my life that is discouraging.  Disappointing.  Problematic.  Difficult.  Painful.  I'm sure you have those, too.  I would encourage you to endure it with grace.  It will pass.  God is there for you in times of trouble.  Psalms 46:1 "God is our refuge and strength, a very present help in times of trouble.  Therefore we will not fear, though the earth be removed, and the mountains be carried into the midst of the sea..."