I don't know the financial situation in the UK, but... in Canada at least, getting a McJob is ridiculously easy. I highly doubt that going from janitorial services to a McJob will be much of a hit financially.
Be very careful with what you spend, if worse comes to worse you can very easily get a job as a cashier, as whatever... plenty of extremely easy to get jobs.
Look for places to rent. There might be some really cheap apartments that provide decent living. If you are just one person, finding someone that rents a room (as a part of a house) won't be that hard.
DON'T TELL ANYONE INSIDE THE CONGREGATION THAT YOU HAVE DOUBTS!
Be completely quiet about your doubts.
YOU WILL BE FINE.
Eventually you'll be able to get back on your feet.