I (35F) separated with my husband last year.

We were friends as teens and officially got together aged 19/20. I went into healthcare and he went into finance. He comes from an incredibly wealthy family and I don't.

Timeline:

13yo - became friends

19yo - dated

20yo - his family trust purchased him a house for 750k and put it in his name. He asked me to move in on day one and I (along with a friend) signed a rental agreement to contribute to bills/maintenance.

21yo - his work quickly became consuming so I took over his chores. we unofficially shared costs of everything. I offered to drop my hours to 4 days per week and pickup some of his domestic duties (quickly became all of them). He quickly took over finances in their entirety and we just ignored the rental agreement. My income was held in one account and used for food, incidentals, daily household stuff, basically all the small purchases and he would take monthly sums and put it into our joint savings account. He used his income for all big purchases and managed the savings.

28yo - we married and got a dog

31yo - we got another dog

32yo - that house sold for 1.37mil. we bought a house for 1.4mil. I believed it was purchased using the 1.37 and a small bridging loan which my husband handled (which he emailed me about). We renovated the house immediately with what was supposedly leftover in the budget. He started to sleep on the sofa full-time so he could watch TV and work at night.

33yo - I took on more demanding work at a higher pay. We both worked full time by this point, but I still did full time domestic duties

34yo - I became ill with a gut problem, lost weight and iron levels tanked. I told him it wasn't optional anymore to split domestic duties while I recover. He didn't want to change the status quo and also wanted a baby. I asked if he would consider not having children because I couldn't do that with the current arrangement and he said that it would be a deal breaker for him, so I packed my bags. He then tells me that the full proceeds from the first house were given to his parents as a repayment and his parents purchased the second house for us outright. He also says all of the renovations and some of our trips away were bankrolled by his parents. He said I didn't need to know, because I benefitted from his financial management at the time.

He proposes that I get 20% of the sale proceeds of the house (valued at 1.9-2mil). He keeps his bank accounts, I keep mine, we split the singular joint account and we don't pool our superannuation.

From my perspective, I believed that the first house was paid out of his personal trust fund and he hit the ground running in his finance career, with lots of cash bonuses and promotions along the way. I assumed his parents gifted him a bit of money here and there for holiday spending money, etc but as he didn't tell me about any large sums I thought we were using our money. I believed that because I was contributing financially as well as almost 100% of the domestic labour 100% of the time, I was also doing my fair share, if not more. Additionally, I put my career on hold to stay in a lower paying position for four days per week as we agreed. As a result, all bank account money should be negotiated, superannuation should be pooled because we spent our whole careers together, any cash he accepted from his parents was a gift and I won't commit to pay back money I didn't know about. 20% of the house is not fair because at best I would (ethically, not legally) owe his parents half of the first house payment (325k) and the rest is really negotiable based on financial and non-financial contributions. 

From his perspective, His bank accounts contain his income and mine contain my income. Superannuation is irrelevant. He feels that his parents deserved the profits from the first house. He sees my non-financial contributions as unimportant, but accounted for in the 20% figure. He sees any and all contributions from his parents as needing to be paid back - not because he was going to pay them back but because they invested in our future together and I left him. 

Am I the villain if I suggest:- He retain all of the furniture/art his parents gave him in the house and almost all of the house/shed contents, he retain his super as he requests, he retain his bank accounts as he requests, but I request 35% of the house proceeds?

I have sought legal representation and have an upcoming appointment, but it's more of an ethical quandary as I worry that on the flipside perhaps I am being naïve?