In Proverbs it says, Trust in the Lord with all your heart and lean not on your own understanding; in all your ways acknowledge him, and he will make your paths straight. Proverbs 3:5-6
When you lean not to your own understanding but rather to God all day, expectations and anger go away. When anger is gone and love is present, you are a light to the world, and you do not bring negativity or pessimism to those around you. It is wrong to complain and be negative. That will eat up your life and ruin your day. Being complaining, grouchy and irritable means that you are not focused on God and are not depending on Him. Complaining is the clear sign you have lost your focus. Start the day with a dependency and focus only on God. This focus will become stronger and stronger, and your words will become more positive every day.
For more, read the History of the One True God, Volume III – God-Fearing Families