Not filing a tax return (and potentially a FBAR) is your main issue. If both of you are US citizens, you should have done that, as you now realize. Your husband should have filed a self-assessment in the UK to report the SS income, assuming you claim the arising basis. Under the US-UK tax treaty, that income is reportable to the US, but only taxed in the UK.
For SS, you need to contact the Federal Benefits Unit at the US Embassy in London. They will sort out the direct deposit to a UK bank. When you retire, you will make the application via the FBU as well.
There are knowledgeable folks who will come along and provide input on ways to become compliant, but I would suggest doing some reading as well to see whether you should have been filing a FBAR (now FIN-CEN 114).