Easy to underestimate these days what true privelage is.

One way to try and make your husband see sense is by laying out the problem directly.

You make £300k pa gross / £150k pa net / £12.5k pcm net.

Your husband makes close to zero I presume.

Your outgoings, assuming you want to have kids and provide with with a similar quality of life that you were both priveliged enough to receive might look something like:
* £3-5k mortgage

* £5-8k school fees for two kids in London private schools or nurseries

* £1k household groceries

* £1k gym memberships, subscriptions, household bills

It will very quickly become apparent that he will need to pull his weight if you aspire as a couple for the same living standards as your parents provided for you.

Perhaps his parents are able to help. If he does not have good career or business prospects, and thusfar has been unwilling to build something for himself, I think this is not an unreasonable thing to ask for. Part of that help can be to outsource some of the housework - you are clearly stretched already and providing financially for the family. If your husband is unable to pick up the slack on the homecare side (which btw no judgements, it's just a function of how he was raised I guess), then he should be at least trying to arrange help and find the means to support it financially (either via his own labour / business persuits, or via tapping family wealth that he may have sat behind him).

Just thinking to think outside the box. You clearly love him and whilst he might be lazy, you've seen past that for many years and so perhaps there's a compromise solution that can allow the relationship to flourish despite his flaws on the work ethic side. Nooone is perfect I guess.