CONGRATULATIONS!!
I'm about 5 weeks too. My partner also refused to accept the idea because of money.
I went about it slightly differently - making him take complete responsibility for the choice. He found he wouldn't be able to book the appointment, give me the tablet, or sit with me in the bathroom while I lost the baby. Reality check time. He decided to keep it (which I would have done anyway of course).
He's getting over the shock now and even smiling occasionally.
Maybe your dear Jerk (like mine) thinks he can make it all go away with no consequences. Because the consequences would all have been yours. Get him to think the whole thing through properly and really ask himself whether he could do that to the baby, to you and to himself. If he really thinks he could then I'm sorry to say he might not be the best guy for you.
Its awful that you feel so unsupported at home but you are definitely supported here, and by your kids too.
Regarding age, my mum had a healthy boy at 45 - easy birth and uneventful pregnancy. He is now in his first year of comprehensive and the picture of health still. Don't listen to the scaremongers.
Many many congratulations and blessings to you! Keep posting!