Fool Zero's comments are awesome. Ask yourself "what is the evidence that I am being ____? What is the evidence that the other people know me better than I know myself? What facts support__________? " This will help separate feelings/ emotions from the facts.
About mindfulness: The writer you just mentioned are all great too. What I have found helpful are guided mindfulness meditations. I struggle with them too ("I'm thinking! I'm judging myself! I'm doing it wrong!) What I have learned in those moments is to imagine you are gently shifting your awareness back to the present item/feeling/ task at hand...even if you have to do it 1000 times. The mind will wander, that is it's nature. Mindfulness is a great Buddhist tradition that was borrowed by the creator of DBT.....and it is good for so many things. It has helped me stop and think , or notice what I am feeling , during interactions with my fiance. I will think "I feel anxious and off-center now. It is likely I will get angry or misinterpret things. Time to play it safe and acknowledge / validate her" It seems to be working......
Again...all the best to you..............