I'm guessing that the magistrates have passed the matter to the Crown Court for sentencing. Therefore my link goes to the Crown Court guidelines (but it actually encompasses the Magistrates' Court guidelines anyway, so it still applies there):
https://www.sentencingcouncil.org.uk/wp-content/uploads/Fraud-bribery-and-money-laundering-offences-Definitive-guideline2.pdf
You'll see that £19k comes within 'Category 4' and that while sentencing for that category can go up to 3 year's imprisonment, the vast majority of sentences available to the court are either non-custodial or not over 2 years (meaning that they can be suspended).
Courts usually try to keep first-time offenders out of prison and, based upon what's in that document (and my own time doing court reporting for local newspapers), I think that it's very unlikely that you're facing an immediate custodial sentence