The lender has offered to reduce your monthly repayments to €538.
How much would it cost you to rent your current house? If you could rent a similar house for a lot less than €538, you should consider handing it back.
If the rent would be more than €538, then you should take it and either a) live in it or b) rent it out at a profit.
If you hand it back, where will your family live? Where did your husband live before you got married? The family home I presume. Is that your best option financially? If that is not an option, where will you live?
The lender cannot "sting" your husband for your debts.
Your options are
1) Accept the deal which will cost you €538 per month
2) Hand back the home and rent elsewhere - which will probably be more expensive
If you agree to a voluntary sale, you will still be liable for the shortfall of €95k. This is a bit academic as you don't have any income to service that debt.
You should offer to sell the home and give them the entire proceeds in exchange for them writing off the shortfall. If they don't agree, tell them that you will be applying for a Personal Insolvency Arrangement or bankruptcy and will need to build up a fund of €3,000 for those costs. So you will be deferring any mortgage repayments until you have that fund built up.
They might come back to you and offer a deal on the shortfall e.g. if you pay €100 per month for 5 years, they will then write off anything remaining.
Brendan