Some posters have acknowledged that this thread is about a couple who do not have DC, so no-one has sacrificed earnings and earning potential for children.
This is a very different scenario to the usual cases of unfair finances where one, usually the woman's earnings are significantly impacted by everything around children: finances are stretched and fairness dictates that the available funds are shared as family money
Furthermore, no one is picking up on the information that he is a few years away from retirement and thirteen years older than OP, who has potentially thirteen more years in which to earn.
Anyone suggesting paying off the mortgage early is always a good use of liquid funds are misinformed. There is not sufficient information in this thread to determine the best use of the funds.
We also do not know the DH's attitude to the decisions which they have taken and the impact these will have in different scenarios. We expect that he is clued up and content with the status quo.
Whose CNN idea was it to get married ? Is his estate beyond the threshold for IHT.
In OP's position, I should do some real research to find out the answer to her concerns around care in old age etc. and even get their understanding confirmed by a lawyer an/or financial advisor. I suggest both because just doing research risks getting it wrong and just talking to an advisor can get expensive if you start from understanding nothing. Your bills will be a lot lower if you only need confirmation. Of key facts and pointers on what else to check out.
Armed with proper advice on the situation in a number of scenarios including the death or incapacity of one of other partner as well as divorce, I would have an informed discussion with DH about the current situation and the way forward together. Lots of couples tend to rely on one partner or the other to deal with finances. It's much better for you both to be informed and then come to an agreement together as informed equals.
While you are at it, Make sure you have everything in place, up to date wills, POA, contact details for bank, house snd financial administration and all the people who would need to be informed. Does his pension provide for a widow or dependents pension? Life insurance.
You have agency here, @TheGodofSmallThings Use it.