As of Monday 4th May 2020, you can now check to see if you are eligible for the self-employed assistance grant form HMRC based on your last three years trading profits.
The grant will give you three months of your average profits over the last three years (2016/17+2017/18+2018/19 divided by three – then 3/12’s at 80% – apparently). To check if you are eligible and enter your contact details for when you can claim, click here https://www.gov.uk/guidance/claim-a-grant-through-the-coronavirus-covid-19-self-employment-income-support-scheme#eligible – you will need your Government Gateway login details and N.I number as well. Good luck!