I was installing tile spacers in an outlet to make it flush with the wall after installing a backsplash in my kitchen. The next 2 outlets stopped working. The 2nd outlet is a GCFI outlet. So I went back to the initial outlet that I had installed spacers in & noticed a black wire had broke. I fixed it. I checked the next outlet which is standard, it now worked. So I checked the next one which is a gcfi with a gfci receptacle tester. It showed 1 light on the right indicating open neutral and then it tripped. It will not reset. Any suggestions on my next move?