You are totally right to feel uneasy and question finances.
I am shocked you paid from your savings during maternity leave, he should have paid all the bills then as he was working then. You need to be more assertive now because this was a poor financial decision and if he is coercing you into paying more than your fair share, that is financial abuse.
He earns 3x what you do, so you should be paying 25% of costs and him 75%
40% you and 60% him, not fair, abusive.
30% you, 60% him and 10% debt, also not fair and abusive.
any period you are earning 0 due to maternity, or illness or loss of job, you guessed it, he pays 100%.
I would scale back the renovation it sound unaffordable.
You should never drain your savings to nothing.
He & you should not borrow money either.
You have a brain, when you say you want a certain kitchen and he points out it’s more money than the budget, the adult response isn’t to demand he drain all his savings too.
ALL renovations go over budget. You sound to be in the early stages. Even if everything goes to plan, most renovations will go between 10-20% over budget.
You guys need to cut your renovations in half at a minimum.