So your husbands half isn't half, that was reduced when you wage went up and took on more of the payments
And he insisted on keep the nanny so he could start his own business?
That makes sense.
In that case I don't think the debt should be paid out of your legacy.
This is a situation of his own making. The fact that his plan is going to continue getting into debt, isn't ok.
The bikes need to go, imo. As a couple you can not afford the garage and it will pay some of the debt off. I don't think sahm should have to give up hobbies but if you can't afford it, you can't afford it.
You need to sit down and discuss this. You need to work out what can be done about childcare. Can you reduce your hours if he can only find something full time. Are you willing to do this? Do you want to do this?
If he finds something full time can you afford your nanny or before/after school clubs for the kids?
But for the time being, as pp said, you need to sort your finances as though he isn't working. Don't base it on when he is working.
He needs to be looking for his own job. No messing about. How you make sure he is actually putting effort in is a different matter. Is he likely to drag his feet? That more than anything will have an effect on your marriage.
If he gets an amazing job it's a bonus. You need to streamline your finances.
You shouldn't have to be flexible while he isn't working. He should be doing all the school picks, unless he is really ill or got an interview etc.
You need to acknowledge that you stuck your head in the sand too, but now that's over and you both have to face up to the truth.
Make a plan and move on. Don't spend your legacy on the debt yet. It's a good idea to have some savings.