Shift your focus from the problem to the solution:

Instead of dwelling on the bad, focus on what you can do to change the situation. Think about solutions, look for ways out, and don't be afraid to take action.

Find your positive "anchor."

This can be any place, activity or person that fills you with positive energy. Spend time in that place, engage in that activity, or connect with that person when you feel discouraged.
Celebrate small victories:

Don't wait for big triumphs to rejoice. Celebrate every step toward your goal, every little thing that makes your day better.

Practice gratitude:

Write in a journal daily or simply say to yourself three things you are grateful for. This will help you focus on the good things in your life and stop complaining.
Slow down and savor the moment:

Often we run through life without noticing the beauty of the world around us. Try to slow down, take time to take in the things that make you happy. Enjoy the taste of coffee, marvel at the colors of a sunset, listen to birdsong. In the little things is the true beauty of life.

Remember that a positive outlook on life is a choice we make every day.