I'm afraid I have to agree with Squeaky, a number of my close friends are photographers (all sorts) and it is extremely rare to get to the point where you can support yourself with photography (let alone make a really good wage).
These are people who are single, no kids, immensely talented, and they are still not making it.
Fashion photography involves years of unpaid labour, long hours, and lots of travel. The chances of being able to break into that world whilst maintaining a family life are very small.
I do sympathise, in an ideal world I would be a writer. Instead I'm doing a postgrad in something slightly more practical and writing as a hobby.
I think you should keep doing photography as a hobby and make use of social media to build a name for yourself -- keep a blog, flickr account, submit photos to competitions, etc. Do voluntary work for organisations. There are lots of things you can do that will eventually bring in some paid work.
I think once you get to THAT stage it would make more sense to do a degree, because then it is building on something.
There are plenty of jobs out there that utilise photography too -- why not do a degree in graphic design or layout or something like that? Then your hobby and your job can intersect and enhance each other.
Normally I always encourage people to follow their dreams, but I have seen firsthand that photography is such a tough field that I think you should proceed cautiously. Your DH is BU to make you feel guilty, but I dont' think he's wrong to think your plans are unrealistic, I'm sorry.