Restart your honing with your highest grit stone. But you will likely need to drop back to one or two hone levels. Since you only mentioned 4k/8k and 12k, start with about 20 on the 12k then test on arm hair. If not smooth, it probably will not be, use the pyramid technique from the top back down until the blade is sharp and smooth for that hone. Then back up the hones.
If your 12k is a cnat consider using the techniques in the "friable grit" thread.
Edit: Use very little pressure to develop slurry with a diamond plate. Heavy pressure leads to larger grit pieces in the slurry. Also be careful of pressure while honing. A scope of some kind will help you diagnose problems.
Jonathan