I wouldn't pay a lump off the mortgage,your savings are currently earning about the same, or even a higher rate, so there wouldn't be a saving in interest.
I also agree that there might be little benefit in increasing your pension pots and it sounds like you can't afford it anyway.
Are you entitled to benefits if you can't work? PIP? You don't say what your current budget looks like in terms of affordability - income vs expenses. Does your DH earn a decent amount from his self employment? Or would he earn more as an employee, which would give him a pension and other benefits like paid leave?
On the pension front, it depends exactly how old you are as to when you can start taking money out of your pension - if you're closer to 53, rather than you've only just turned 52, it's 55 in the former case, but jumps to 57 in the latter so it could either be in just over 2 years time or 5, which looks quite different.
How much is your current home worth and is it likely to be affordable to buy a bungalow - eg if you're in an expensive area so can move to a slightly cheaper area where a bungalow would cost less than your current home so you could reduce/pay off your mortgage?
If not, shared ownership could be an option - possibly a new build as they are more accessible than older properties - would a modern standard small house with accessible entrance, downstairs bathroom and stairlift suit?
The other option could be to stay where you are and use your money to adapt your property - downstairs bathroom? Stairlift? Or to replace your income - run down the £40k gradually to fill the gap in your budget, rather than paying a lump off your mortgage?