is his job dull? Yes! Has he worked hard? Also yes. Does that mean I want him to bridge the financial gap for 10 yrs using this lump sum so he can do… I don’t know what? No.
Of course we don’t know how you are talking to your husband about this, and can only base things on what and how you are saying things on here. But based on that, I wonder whether some of the issue lies in how inflexible you are both being?
He dislikes his dull job, which he has worked hard in, and which has contributed to your already good financial situation, and wants to retire. He is saying he doesn’t want to carry on in his career. And, instead of recognising that, you are sweeping all of his feelings aside, and at the same time stripping away any of the joy that the money can bring (presumably a bonus after a difficult bereavement), and telling him that he should put all (most) of that money into his children and continue on in his job for another 10(?) years.
There’s no compromise and no understanding of the underlying thing he’s saying: he needs a change.
You sound like one of those people who I always think of as rather negative voices. What I mean by that is that you highlight the negatives against ideas but don’t actually bring any ideas to the table. There’s usually one in every workplace or friendship group, one of those that says ‘no’ to everyone else’s ideas but contributes absolutely nothing themself.
You need to give him something rather than just saying ‘no’ and only presenting him with an alternative that means giving everything away.
Surely there is a middle ground that might, for instance involve a career change or cutting back on work, while also giving some to your children?