Surely if your mortgage is a fixed rate until 2025. Even if it is January 2025 then this discussion and potential move should be put off till at least January 2024 at the earliest
As you have experienced a lot can happen in a year. You need to take time to yourself to feel stronger and another house move in such a short period of time after all you have been through isn’t going to help. Neither is a Dh fretting over something that doesn’t need to be fretted about at this time.
Remember if mortgage rates go up then yes the value of your house will go down, but so will every other house.
Definitely sit down and go through the figures now to see if there is any way to cut down and save or reduce the existing mortgage and look at what ifs for 2025.
Even if you found that your mortgage rate goes up 5% or 10% from what you are paying you will have a figure that you can work with whether that figure is -£2000 or -£1000 per month or -£12.50 per month.
I have been in this position a few times and helped friend to turn a monthly minus figure into a plus after her divorce.
I look at firstly what I can cut down on or use a cheaper alternatives (eg £360 per year savings using horse grass pellets instead of the cheapest cat litter). Finding the cheapest you can buy something that is non perishable and bulk buying a years supply etc
Comparison websites for insurances, phone and power etc. Costco membership for even just fuel if you have one with a petrol station near you
Then what you can use that you have to bring extra income in.
Friend rents out her driveway for parking as she is close to a station carpark and is £2 per day cheaper than the station carpark. She also Airbnb’s a bedroom she has that has an en-suite and another bedroom is the living room with a small kitchenette and microwave in. For her it might only be £500 per month (minimum) she gets in between these 2 things but it is the difference between staying in the house she loves or having to sell and buy something that most likely has the same out goings but just gives her a savings pot she can dip into to keep her going.
A few friends have eBay businesses. (One had her business grow so large her Dh gave up his job to work full time with her.
Even 1 or 2 evenings or a weekend day working at something completely different or on a freelance basis adds to the pot.
I never look at the minus figure as an enormous non achievable figure but break it down into what smaller amounts I can cut it down to by earning or cutting down on outgoings so that figure gets smaller and smaller until it disappears.