Originally Posted by
Albus Dumbledore
I often feel this way. For me, I think it stems from not having any kind of emotional validation when I was younger. When I start having those thoughts, I try to challenge them with logic (asking myself what reason I would have for lying etc), which sometimes helps. There was also a skill that I learnt in DBT which was about working out the function of our emotions which might help -
http://www.dbtselfhelp.com/html/emotion_function.html . The idea is that all emotions have a purpose, and are valid, so it might help with those thoughts.