What am i entitled to if we divorce. Perhaps a question for IAAL

Some background...
I am almost married one year. My husband MADE me sign a prenup. My stipulation was that my name had to appear on the deed and so he did.

As in most cases, what we came into the marriage with is seperate property. He has a brokerage account with substantial money in it and i can't touch it. We also agreed that he is NOT to put any more money into it but that we save money in an account with both our names on it. I do not work and haven't since we were married. Legally and technically his money is marital income and it's my money as well.

Here is the issue. He wants to refinance the house. He originally purchased it for $200,000 + about 6 years ago. It has escalated in value to over $600,000. He wants to take out the difference which would amount to $400,000. He wants to take this money and put it into his brokerage account to invest it in the market.

I have checked with legal counsel and he CAN'T do this without my consent because my name is on the deed and I would also be named on the mortgage.

We have also had serious marital difficulties. The last couple of weeks he has been threatening me with seperation/divorce.
I am afraid that he is in a hurry to seperate with me to get my name off the deed (I had to agree to this in the prenup that in the event of divorce I sign the house back to him without question).
I also understand from legal counsel that i do not have to sign anything if i don't want to because i do not want to seperate.

My question here is that if in the event this does work itself out (the marriage) and he goes ahead and puts it into his brokerage account (one legal counsel also said that he can't put it into a seperate account because it is considered a loan which is being repaid with marital income), would i be entitled whatever equity has been put back into the house. He plans to invest this money. So, let's say that he invests $400,000 and the investment grows to $600,000, would i be entitled to 1/2 of the growth plus the equity that rebuilt into the house.