Have any of the leaves turned black/brown? My privet suffered from honey fungus and I had to dig out the hedge, as well as a section of healthy hedge, and I also dug out and threw away all the soil. It was a 2 day job!
I didnt see any bootlaces either, but all the other sympotms were there. HF can spread from dead tree stumps or decaying cherry trees. I had both!
I replaced with privet from elsewhere in the garden and fortunately all now seems well.