Accept compliments regardless of how you feel about their validity. Thank the person rather than rejecting their claim; both of you will feel better for it.
Similarly, try not to invalidate people, even when you disagree with them. With tact you can acknowledge someone's ideas without condoning them. You will be more effective at getting your point across this way.
Ask questions and be wary when you find youself mind reading, though trust that you can and will at times have to rely on intuition.
Do not become overly attached to the identity you have created for yourself. While it may bring necessary meaning to your life, confining yourself too much to an image will inevitably stifle growth and ensure that the shock is that much greater when unforseen events challenge your self perception and world view. People who are more willing to accept radical change, such as the loss of a limb, are better able to move on with their lives and reclaim their happiness.
Show empathy for others but prioritize your needs. The better you take care of yourself the more capable you are of helping others. If you have the ability to do so, know when to walk away from people and situations that are detrimental to your health. Unfortunately that includes family and friends at times.
Maintain some skeptism in your life; the world is more gray than it is black and white, and conventional wisdom isn't always wise. Sometimes it pays to go against the grain, despite everyone telling you otherwise.
Having some semblance of hope, even when the odds are against you, is better than resorting to a life of cynicism.
Isolation is terrible for your health and a surefire way to worsen whatever conditions are leading you to this behavior.
Be patient with yourself always; breaking maladaptive habits and building healthier ones takes time and diligence. Expect setbacks, but analyze what went wrong and create new strategies accordingly. Same goes with unhealthy thought patterns. Remember the brain is somewhat neuroplastic. If you are hard on yourself, and often have a kind of abusive internal dialogue going, try talking to the kid version of you. It should shift the dialogue to be a lot more nurturing.
Fake it till you make it has some truth to it. Little things like sitting upright trigger hormonal changes in the body, which then in turn help increase measures of confidence and can actually improve your mindset.
Distractions are useful for taking your mind off things you rather not think about, but use them sparingly as reliance leads to inaction and will never resolve your problems.