I know it sounds harsh, but I've done enough work on this myself, and coached enough business women, to believe this is 100% true.
Two books really helped transform my mindset around money at that was Napolean Hill's "Think and Grow Rich" and Barbara Stanny's book, "Over Coming Under Earning".
After reading those, I became a Sacred Money Archetype coach and dived in to re-writing my own money story and committing to helping as many women as I could to do the same.
I hear you ask. Well, your soul's purpose is to live a life on and of purpose and to experience it's fullest expansion and expression.
It can't do that if it's constantly being told "I can't afford it".
Besides which, I'm pretty sure that when you set up in business, you didn't have the goal to under earn and over work?
I became a coach in SMA at least 3 years ago and it was such an incredible insight to my own beliefs, fears and motivations around money.
Once I understood what my Archetypes strengths and challenges were I was able to change my whole attitude toward money and uplevel my mindset and income dramatically.
If you'd like to discover your SMA profile, you can take the quiz here.