Hello Dandy
Current advice for people with diabetes is to practice ’social distancing’ as much as possible:
www.gov.uk
My understanding is that well managed T1 does not put a person at significantly increased risk of a severe case of Coronavirus, but that we should all try to avoid contracting the disease while the health service is under so much pressure, because the proportion of T1s who unfortunately DO develop a severe case, would have the significant complication of T1 along for the ride.
It sounds like your husband‘s work requires him to go out and mix with the public, so he will just have to decide not to work (current protection for self employed is less than ideal

), or take extra precautions while working - and especially check to ensure that no property he visits has anyone in it that has symptoms.
then extra scrupolous hand washing and no touching of eyes/mouth/nose too.
Must be very difficult for you both