This kind of thinking can definitely point you in the direction of unhappiness. It can be hard to detect in oneself but others see it much more clearly. It is often but not always a hallmark of depression. Chronic complaining is negative thinking although complaints are certainly appropriate at times. An effective tool is to first learn to recognize it and then cognitively change your perspective. Self talk techniques can be extremely helpful. In the beginning it’s hard to catch it all but as time goes on you can get better and better at it. There is a great deal of research on positive thinking and positive results. Optimists are generally happier people.