I did two things to resolve my debuger running very slowly

1: Select Tools>Configure Browsers...>Run & Debug(Settings) and then Reset (at the bottom of the dialogue box)

2: Go to the bottom of the PhpED screen and right click in the ribbon. In the long list of functions select Breakpoints. Right click in the Breakpoints dialogue box and select clear all.

Then close PhpED and reopen it.

Worked for me! Yippee!