Since our thoughts create our reality, which philosophy you choose will determine what you see. In truth, you don't see with your eyes, you see with your mind. You will have negative emotions if you think with your negative ego mind. You will have positive emotions if you think with your Spiritual Mind. Your thoughts create your feelings, emotions, behavior, and physical health or lack thereof.
Psychological health is nothing more than maintaining a good mental diet.
As the Master Jesus said in A Course in Miracles, the key is to deny any thought that is not of God to enter your mind. The key is to be vigilant for God and His Kingdom at all times and never to go on automatic pilot. Whenever a negative ego thought tries to enter your mind just deny it entrance and push it out. This is the concept of denial and affirmation. It is occurring literally a million times a day.