Money struggles

So we have put down a £2000 deposit on our wedding and booked the registrar. Since then my mother in law to be has been very ill and my partner got made redundant. Instead of getting a new job he has become her carer. However now it means he’s not earning money so we’re struggling to find the rest of the money to pay for the venue! I have the dress, bridesmaids dresses, etc. But there’s no way I can afford to pay for the wedding and now he can’t either! We have to settle half the balance in January and that’s £3500. I just don’t know what to do? I can’t even get excited about wedding planning anymore as I just feel I don’t know whether it will happen. My Other half said we may need to push it back a year but I’m just worried the same thing will happen again! Im trying my best to make extra money but I have two children at home so it’s hard, and I can make extra little bits of money but not anywhere near the amount we need. It’s just becoming so stressful and this is meant to be exciting! Im just so unsure of what to do for the best. Advice please.