What is the most logical next event?

How to admit the truth over the phone
Write down what you want to say.
It helps to get it all out beforehand so you can feel more prepared. Try writing down shorthand notes of what you want to say, or write it out word-for-word and read it when you speak to them on the phone.
Even if you don't stick to your " script " when the call actually happens, you'll at least have a reference point so you don't forget to say anything important. Don't just write down the facts, or confessions.