Had a lipoma operated from left flank 6 weeks ago. I now have pain and a burning sensation. Do I have an infection? (photo)

Thank you for sharing your question and photograph and I am sorry to hear of your recovery difficulties.  You are right that after 6 weeks you should not be experiencing significant discomfort and I would return to your surgeon for an in-person evaluation.  I do not see any signs of infection but you may have a suture related issue or tissue sensitivity that would benefit from scar massage.  Hope this helps.

Based upon your incision photo, you have no evidence of an infection. Sometimes a patient can get temporary burning pain at the site of surgery which should resolve with time. Consult your surgeon if the pain does not resolve or you develop any drainage or discoloration around the incision. Good luck and take care.

Go back and see the treating surgeon. Some of the thing you describe are sensory nerve irritation or damage which  can occur with any surgical procedure. If this is the case, it will subside over time. There is "railroad tracking" due to large sutures which were placed for skin closure.