I'm sorry about your husband losing his job and the stress you must feel.
Do you have savings to cover the full mortgage payments (and bills) for any length of time? If so, give him a month or two to find a new job and then re-evaluate what you need to do from a financial perspective. He should also sign up with some agencies and do temp work. (I appreciate that's not a long-term solution, but if he's in a particular industry, sign up to angencies that support that field and temp/contract/freelance contracts will provide at least some money to help until he finds something permanent.)
If you can't cover the mortgage and bills from the next payment, then you need to either (a) request your payments be switched to interest only for up to 6 months (bear in mind that, after 6 months, your payments will go back to repayment terms and the monthly amount will be slightly higher, to cover the 6 months you were paying a bit less); or (b) extend the term of your mortgage (after 6 months you can revert to the original term, keep the new term or change it to something different). No financial checks are made and it has no impact on your credit score. You just contact your provider and say, under the Mortgage Charter, your'd like to switch your mortgage to e.g. 6 months interest only.
https://www.barclays.co.uk/mortgages/mortgage-charter/
If you can't speak to anyone on the phone, can you email or login to your mortgage account and send a message that way? It's a really simple, straight forward process. I literally emailed my mortgage provider and the change was made with effect from the next payment. That was it. (I was shocked that going interest only didn't actually save me that much, but it was better than nothing when I was in a tight spot.)
If you haven't already got a budget, make one now by going through the last 3 months worth of bank and credit card statements and listing all of your regular and ad-hoc spending. That might show you some areas you can cut back in.
Also make an application for Universal Credit.
https://www.gov.uk/government/publications/universal-credit-and-couples-an-introduction/universal-credit-further-information-for-couples