Hi, I think there are multiple ways to lose views like this and if you look at your own life, I am sure you can point at some belief that you had and lost it and created a new one that holds more weight in the reality you live in. However, with stuff like this, you probably learned this early in life and had enough reinforced influence on you, that it is deeply ingrained in you. I guess the only thing I have this feeling about is "You are what you are and there is no changing that". I thought I was the nice guy, the kind friend and that women will love me once they are 28. I thought your characteristics are you and there is no way to change it, only level it up. And the reason was most likely because I had no idea how to become more confident or charismatic or anything else. And I somewhat lost this belief and shifted it into "Will I be able to achieve that?".
I will rant here a bit but there is a point: Thing is, I am quite stubborn. Once I figure something out, I think that is how things are and I fight others who try to convey different message that contradicts it. Which is normal (based on cognitive biases) but I just think *I* am the one that has it right. And some things, I feel like I am right about them.. like... Everyone likes different things. And then those that are purely based on something I achieved like... I got many people out of depression. Once a guy from jumping from a bridge to a point where he became a very sucessful financial consultant earning millions and now invites me to the company summits for a weekend in Paris every 6 months. But that is just my belief in my abilities and I might not be able to help everyone like this. There was a case where a friend of mine was raped by her father and even though I tried, she still commited suicide. --- The point of this whole non-sense about me is, if you trully, deep down in your heart believe that is how it is and that a guy has to make more money than a woman otherwise he is not a real man or you sense there is something else to masculinity in general, to that part that makes you a real man if you make more money than your girl, like... not the money itself, but the ability to be able to have financial success. Being able to do such a great work that people want to pay you loads of cash for it. And if you take the money part of it, you just have the ability to be successful. And then you define what success means to you. And you might realize that for you, being a man means fixing their car for example because you like cars, fixing stuff and to help others in need. Which is basically reframing this whole idea about money and being a real man but ... as I said, if it is deeply set in you, than there is this milisecond when people talk about who makes more money in their relationships, the guy or the girl. And in that milisecond, if you hold this belief and they say .. "Oh, its Lucy" you suddenly feel like he is less of a guy for that milisecond. It just hits you, you probably dont even know why. Just like when when a girl said she likes sex very much and I thought she was a slut and she is not "worthy". If you dont want to have certain belief, you should go deep in you, put a spotlight on it and investigate the core reason you feel that way and if it really holds any ground in your current reality.
Another way, which I am not sure about right now, because someone will probably tell me that there is an underlying issue with it - talk about it with your girl. And now I dont mean "I dont think I am man enough for you because you make more money" because that is what I meant by that underlying issue, that you could make yourself look insecure. But if say that you were raised certain way and that the man is the head of the house and should make more money for the family BUT you question it and want to know how important this issue is to her, how ok she is with it (just an example, I am sure people here could phrase it in a better way). Point is, you get some feedback from someone that you care about and who cares about you and it might help you overcome this belief because "what someone who cares about us" is more important than "what I believe". I used this when I felt very insecure about me, because I felt like I have no value in normal situations and people basically told me that if I chill and do what I did "on Thursday" (because I was chill and had fun with them that day and did not bring up any psychological stuff), then I am good and that I should not feel like I need to prove my worth to them.
On a final note, I only want you to consider this as my perspective on it.