OP.
Honestly - as you have a disability, you're already facing a disadvantage in the workforce. It would serve you better to work to give yourself as many additional advantages as possible.
Paying back your loan is more like just another outgoing once you're working, you are married already so presumably already manage a household Budget? It's really just another bill and not huge and is graduated based on what you earn.
Your dh is not talking from a position of experience and ultimately its your decision. That said, what does your dh do? Does his job tie you down to an area geographically?
I have done uni twice. First time in 20's nursing. Tough, very hard work but met amazing people and had a great experience. No debt though as early 90's and for vocational courses like that the govt needed us! 
2nd time in 30's as a single mum so tough for different reasons, course less intense but busy with dd. Still absolutely worth doing. Met more amazing people, got a lot out of both the course and the experience. Led to a very good job (unfortunately as a result of an accident I am now disabled and have mh issues).
With the course you are looking at doing there are FAR more options than teaching, though teaching is an excellent career to go into. There are corporate, educational, govt and overseas options you could look into.
But initially what matters is doing a degree you enjoy, are passionate about, academically suited to, will get a lot out of.
And as other graduates have said, university is about SO much more than the course, it exposes you to a wider experience of life, broadens your mind, makes you question everything and if you're really lucky you will likely make lifelong friends too (not just other students either).
The truth is these days without a degree you can get a job, even a very good job, but with a degree you can get a career, opportunities, choices.