1. You dont have to accept the pay cut but the alternative is redundancy.
2. You can be made to use annual leave, and doing so could be a good solution financially if its paid at full pay rather than the reduced furlough rate. Check that with them.
I have been furloughed now for four weeks and find I'm spending less. No socialising, no eating out, no petrol or travel expenses. I hope you find the same and that the reduced salary is enough to cover your basic needs and protects your job.