I get the tie-in though. You have negative tapes playing in your head, it causes you to interpret things in your relationship weirdly / causes you to have to analyze your thoughts & actions in your relationship to ensure that you're accurately interpreting instead of reacting to negative tapes ....
That can get exhausting. And yes, it can create insecurities in a relationship that is actually going quite well. I myself am beginning to deal with this very thing as I embark upon what I think is going to be a relationship of some worth. (See what I did there ... "what I think" ... now where do you think that doubt is coming from lol).
It's true a good IC can help you challenge those negative thoughts and if you can afford it, you should pursue that avenue.
But you can do this yourself too. So when you think "gah! I am worthless and ugly, just like xWH (my mom, or whoever) said", purposefully stop and ask yourself. Really? Is this really true? Do I really believe this? Or am I just scared because tomorrow I have to give a big presentation at work. Something that I've done successfully many times before. So many times in fact that fuck it, I'm not worthless and ugly. I'm smart, talented, and can get the job done."
That's kind of simplistic, but you get the idea. Negative self talk takes purposeful intent and strength of will to overcome. You have to re-program your brain, re-program the way your synapses are firing if you will. It takes time. But it's doable. And you've survived a lot to get to your NB so you can conquer this too.