Help

So I have a really big event coming this Saturday, it’s a really big thing which I CANNOT let myself skip and forget. And yesterday after four hour practice I got mild sore throat, I may think it’s something with vocal cords cause it doesn’t feel like sore throat to me. And I need to attend that event! Because I know I said to myself I need to get some rest till Saturday and don’t go to 4 hour practice tomorrow just to make sure my voice heals a bit before I sing. So can somebody yall give me good working advice’s for my situation. And no I don’t know how to gargle so now gargling please! Thanks for yall all advice for future but if I won’t check Reddit for a bit it may be because I drink hot tea and honey, thanks!