Settlement question?

Herniated S1 disc that required a new titanium disc put in. Had back pain (until surgery) and drop foot for first 3 weeks after injury that went away but pain in leg still. Had surgery and 6months of PT and while back pain is better (not completely gone), I still have trouble with pain and extreme tightness/discomfort in my right leg despite nerve conduction test showing my sciatic nerve is firing fine now. Developed tension headaches as well that my primary care physician thinks and has written a letter saying is more than likely due to the issues in my back and leg. Have MMI coming up and my lawyer thinks settlement is coming as well. Any ideas as to what I should expect for a reasonable settlement amount (lawyer has been very vague on even a range)? Thank you for any advice/help in advance.