You need to get legal advice. Start by Citizen's Advice Bureau.
This is the number for England: 0800 144 8848
If you can't afford legal advice you will should have access to free legal action.
His offer is not a joke, it is beyond it. It is an insult of the highest order.
I don't know the Law of the UK, but where I originally come from you are entitled to 50% of the wealth of the couple when you divorce.
Even here in the UK people have rights.
I would say get legal information, but I would be inclined not to accept those £7000 - they are nothing after all, as that could stop you to from receiving your fair amount down the line - but this is my opinion, not legally informed.
I would recomend that you pop over to Youtube, to HG Tudors channel and check if you think that your ex is a narcissist. You have said two things that raise the flag for me. If he is, it is a totally different kettle of fish that you are dealing with, you must gather strenth! And that would totally justify your position now.
You are lucky there are no children - makes the matter much simpler.
You have given you 7 years of your like to be a home maker, to be his wife.
You have given up your financial and personal independance, your professional status, you trusted him to earn the money, to look after your family's patrimony. He let you down badly. You are due a suitable divorce settlement, and is not £7000 - that is ridiculous beyond measure. He would pay more than that in two months for a nanny's wage if he had children. Let us not mention the private schools fees.
I have read some very dim comments regarding why you didn't work.
You don't have to work, some couples chose to have a stay at home wife.
People who don't understand that are just plain stupid.
Gather yourself together, fight for your rights, you were not his prostitue nor his slave - and he would pay a lot more for the services of a prostitute!
My mother has never worked, she is a stay at home wife. It doesn't make her lazy or stupid. She has been a very kind and generous person who dedicated her life to make the happiness and comfort of others.
Look up for charities and information on getting support:
https://www.money.co.uk/guides/how-to-get-a-fair-financial-divorce-settlement
Good Luck,
You seem to have lost a lously husband. It will only get better from now!