"Keep fighting," she says; and How to change your negative core beliefs

It's not that I don't value myself. I do. But deep inside I am insecure and Dr. She says I "fear being worthless" or having no value to anyone.  She says I have a core belief about this that is in my heart. And when anything happens that will take a hit to my self esteem or sense of self worth that core is going to come out and tell me I am worthless and that what ever is happening is happening because I am worthless and/or unlovable or whatever that negative core belief is.

Yes. She is probably correct. And my brain, being the analyzer it is will often quickly agree: "Yes, that must be true because it is a basic law of economics. Supply and demand. It doesn't matter how amazing or awesome the product is, if no one is calling for it, there is no demand, it has no value." And I am so keenly aware of so many things. It is not just one thing that suggest this to my logical brain there are many. Including, but not limited to, how our flawed primary educational systems feed it. Remember all those dumb work sheets? "Good, better, best." All the sorting and categorizing? "Cut and paste all the picture that start with P, throw out the ones that don't belong"

Then I have to rationalize with things like: "I built that shed" to which the core will reply, "with your dad who was impatient and mad at you most of the time, despite how patient he has become with everyone else over the years."
So I'll try: "I biked 2 countries in 2 months with my 2 kids" to which my core will reply "and lost many friends because you tagged along and they didn't actually want you there, but you were too stupid to respond to the red flags."
"But I have at least walked a mile in the shoes of an elementary school teacher"
"And they did not offer to hold your job while you were in Brazil, plus the two teachers that shot down 100% (wish I were exaggerating there) of your ideas."

..."I am tired of fighting." I tell Dr. She today
 She said I have to keep fighting and fight harder again.
She meant it.
And while I am tired of fighting that was really all I needed to hear.
And she is correct.
So to my thoughts I say:
"now wait a minute, I didn't claim anything more than walking a mile in teacher shoes, and I fully admit that about did me in. My back gave out twice and I had more colds and lost my voice with those more times than I think I have in the rest of my life combined. And I was putting in 14 hour days, did you really want to go back to that? I did not ask them to hold the job either. Plus, those two teachers, that did, in fact, shoot down 100% (I also wish I were exaggerating) of my ideas also snagged many of those ideas out from under me and even pulled them out meetings with the big guys to make themselves look good. There is something to that which actually says a lot of good things about me."

"And I love my shed. I designed it and did a lot of the inside myself. Also it's probably good my dad feels safe enough with me to be ornery and impatient with me. He doesn't have that safety other places."

"As far as the friends, good riddance. You were there, you saw their true colors and you only biked with them for 1 out of the 2.5 months. You did this with your kids, by yourself, and you and I both know (or rather I and I know) they kind of hated you for that because it overshadowed them a bit and stole some of there glory, even though you weren't trying to."
"So core belief, you are wrong again and I am not okay with you being wrong about this so you will have to keep working on changing or be gone."
"You are right myself" and my core is softening, remembering why it has been so determined to change for me, and agreeing with Dr. She, to fight harder.
Because I am worth it.