Our very survival depends on the ability to filter out the overwhelming amount of information that all our senses are receiving at any given moment.
Being conscious of thought and of feelings is not the normal state of most people, but it is a very possible and peaceful place to be.
Practice focusing your attention on peaceful and grateful thoughts, affirmations or just re-appreciating any and every good thing that's in your life right now. We can only process so much. We can only give our attention and energy to so much.
A mind full of worry has no room for hope. A mind full of doubt has no room for confidence. A mind full of gratitude sees no lack. A mind full of curiosity, love, humor, and goodness will always manage to deal with adversity as it comes but returns to the habit-formed state of peace.
Like any habit, it takes at first a lot of conscious energy and effort, but soon becomes the natural state of being. It's a wonderful goal to achieve.