Chronic groin pain after inguinal hernia repair is a common complication.
The exact cause for the pain is not clear, but, it is believed to be due to nerve entrapment, either in the sutures, mesh or scar tissue.
Some surgeons suggest injection of local anaesthetic or nerve blocks, into the area of maximal tenderness on clinical examination, with or without the addition of anti-neuropathic medication (neurotin).
Also, this pain can be due to adherence of the bowel to the edge of the prosthetic (mesh), adherence of the bowel to the tacks, or relapse of hernia.
Pain resulting from sutures and suture material in skin, and muscular pain due to extension of tacks into the muscles, need to be taken in consideration.
This can be corrected by your surgeon.
Nausea could be a symptom of small bowel obstruction, caused by mesh migration or adhesions.
Visit your surgeon or ask foe second opinion!