Loupdemer,
I'll be interested in what your doctor tells you. It's been over a year since my surgery and I still have pain identical to what you describe. I've been back to my surgeon, as well as, several other doctors with no answer. They've done an MRI, CT scan, physical exam etc. without any results (but, obviously, no hernia).
Doctors have treated this with "trigger point" steroidal injections, which give about 10 days - 2 weeks of relief.
At this point, I think the doctors are beginning to believe this pain is imaginary! I'm sorry you're experiencing this, but I'm glad to know I'm not imagining this.
Again, please let me know if you/your doctor finds anything definitive.
Bogart