Thanks for everyone's comments. It's made for interesting and lengthy(!) reading.
Apologies to those who have been offended by my attitude.
To come to back to a few points:
Yes my DH has paid his loan off.
Yes my loan is only repayable once I reach a certain salary and it will be written off eventually if I don't earn above he threshold.
No I didn't do a degree intending to start a family immediately. I intended to use it for my career.
It's a fair point to say I'm naive about future work plans. Yes, you're right, I may end up working full time and therefore may pay it off anyway.
I had DC1 at 28 and had DC3 6 months ago so plan to be at home until all are at school. Then I hope to work part time if possible.
I agree voluntary community work does not make up for not paying back my student loan but I hope I am contributing in ways I can (alongside bringing up 3 kids) while I am not paying back the money.
Yes I am in a vulnerable position if our relationship breaks down. Our marriage is not bulletproof but we work as a team taking different roles and responsibilities. It is a risk, but one I'm prepared to take to be at home with our kids now. We'd both be pretty screwed without each other tbh. I absolutely accept it's not for everyone.
I think that's me over and out.