OP, I think you’re worrying more than you need to about this.
You’re a community cater, so visiting elderly / ill people in their homes, yes?
Realistically, the patients you visit are at low risk of spreading Coronavirus. If they’re infirm or ill enough to need a career, they’re probably not going out and about a lot and getting lots of exposure to it.
There’s not been many cases in the UK yet, and AFAIK most of those are people who’ve returned from trips abroad to affected areas.
So really your patients are unlikely to give Coronavirus to you. You’d be more likely to catch it from your colleagues at the admin job, or day to day things like going to shops or other public places. And while it is of course a worry you can’t practically shut yourself off from everything until it goes away.
The sensible thing to do would be to be vigilant about personal hygiene, hand washing and so on, and follow all the procedures and guidelines you have from your employer.