@indignatio
In the kindest possible way, can you approach this as the fact there are three financial interests in this relationship. You, him and the trust. See them as separate entities.
This is the best way to look at it OP. As 3 different ‘people/entities’. And 2 of them are for your husband’s benefit. So you need to create a fourth one, that is for your benefit. Then, if the worst happens (and I hope it doesn’t!) you have options.
You’ve had advice here about what your fourth entity, or your “trust” could be - an asset like a house or money in retirement or separate savings, but there are three more important things here. One is that you get proper financial advice as to whatever you are saving in (house/retirement/bank account) will be all yours (and not claimable in a divorce/separation), in the same way the house is all his.
Secondly, you need to consistently save until you have approx the same value as a paid for home (or a paid for home, if that’s what you chose to put the money into). Don’t miss a month, don’t stop ‘because it’s Christmas’ or you are saving for a holiday - the money comes out every pay just like a mortgage or rent payment would. Compulsory. No exceptions.
Thirdly, don’t put the earnings of your asset back into the joint pot. If your house gives you income from the renter, that money goes back into the mortgage. If your investments pay interest, don’t see it as income, but more money to invest. Think if it like his trust - that house doesn’t pay you, so your investment shouldn’t either.
Doing this would mean that if you did separate in 5, 10 or 15 or 20 years, you would have a paid for, or partially paid for house to move into, while he kept your home. I assume all other assets (furniture, cash in accounts etc) would be split. It would even up the inequity that his/the trust’s ownership of the house has left you.
Apart from this one bit of savings from your pay, that is going to your one asset, everything else can be joined in your life. And if the worst never happens, you have a solid asset, a saving history and an asset to leave in future. It’s win/win.