It sounds like, while you've had discussions on specific things at various points in time, that you've never sat down to a discussion with her about your financial affairs as a totality.
It sounds like the two of you need to talk about your feelings in a completely open way, figure out what bothers each of you and why.
I wouldn't go into a brainstorming session like that with any plans or proposals. That can come later.
For example, if you go into a conversation saying, 'I feel our financial arrangement is unfair,' she may be like, 'what? I didn't realize.' And you can talk about how each of you sees things. If you go into it saying, 'I feel our financial arrangement is unfair and I think we should do x, y, and z going forward,' even if you are very relaxed and respectful about it, the message probably won't go down as well. She'll be like, 'well, this is news to me! I've never thought it's unfair, and furthermore who do you think you are to dictate terms, we're equal partners!' and all the trust issues get triggered, etc.