Husband & Wife mattress mis-match … Help!

My husband and I have been hunting for a mattress for honestly a couple of years now. With our current mattress becoming increasingly uncomfortible we have arrived at what I can only describe as the point of desperation.
My husband stands about 5’10" and weighs 280 pounds, he mostly sleeps on his back with a CPAP and currently there is a gully on his side of the mattress (which I do rotate periodically so really there are now two gullies). He doesn’t really have back or neck issues but if the gully gets any bigger I suspect he will soon. We both agree though that I am actually the “problem.” I am 5’5" tall weigh about 130 pounds and suffer from chronic neck and back issues. I had a bulging disc in my low back about ten years ago which prompted the purchase of the mattress we currently have. I no longer have shooting pain down my leg, instead I am left with a nagging tightness in my low back that is exacerbated by laying down in general. I tend to sleep on my right side which currently jams my shoulder into my ear but it is better then the stress on my back if I try and fall asleep laying flat. I go to sleep uncomfortable every night and wake up in pain every morning. I have some degenerative disc issues in my neck which means in addition to chronic neck pain I often wake up with a slightly numb left index finger.
We currently have a Stearns & Foster Estate Kimberley Luxury Firm mattress that we purchased around 2010. I was still in physical therapy for my initial disc issue, still in pain and thought that the mattress seemed ok but of course as my disc issue resolved my quality of sleep did not improve. It turns out that it was not a good mattress for me and I have not really had a good night’s sleep since.
I have laid on a lot of mattresses over the last two years and have only found 2 that did not cause me immediate pain. The first was a Stearns & Foster Hurston Plush which is much too soft for my husband and a Sleep Number Bed set on 40. We are not too keen on the Sleep Number Bed since it seems lately that everything we buy breaks, a bed with moving parts, pumps etc seems like more trouble then it might be worth. Everything else has provided zero support under my low back and forces my hips into an unnatural position. Unfortunately it seems that only a soft mattress has enough give to allow my hips to sink down enough to put my spine into alignment and anything that soft would never hold up under the weight of my much larger husband. I am truly at my wits end. There are mornings that my husband has to help me out of bed because I am so stiff. I am only 56 years old, I exercise regularly, eat a healthy diet and I am exhausted from lack of quality sleep.

So what do you think? Is there an answer to this problem? What do couples do when they have very specific but very different needs. I have read through many of the MAttress Underground posts and have started to go through the five steps to picking a mattress info (I have already learned so much!) but the end result is going to be a bed that only works for me … divorce and separate bedrooms are not an option and neither is separate beds - no space in our room for two twins).
We need a queen mattress with a split box spring (old house - small rooms).

Hi. Thanks for reaching out. Let’s see if we can help you find the right solution to your issue.
It seems that your support and firmness preferences / needs are far apart. Most couples usually can find a happy medium by picking a mattress with good support and high quality comfort layers to pair. But in this case, medical needs and size differential may not make that possible. So I’m going to offer you a few different solutions.
The first would be to seek out one the respected latex experts on this forum and build out a queen size latex mattress with split internal layers. It allows you the most customization between the two sides without doing two separate mattresses.
The second option is doing 2 split queen mattresses. You would have to seek out a smaller company that builds their own mattresses like ourselves. Split queen mattresses are not standard for most companies. We have done it in the past by taking two different builds, and adjusting slightly to make sure the finish height is equal between the two beds. It works out well. The only downside is the two mattresses feel small being only 30" wide. If you guys were doing a king, this would be my top choice. But because it is a queen, I would lead towards the split internal layers.