You problably don't want to hear from me, but I've had experience with several of the things you mentioned. First,the Nortriptyline. Do you normally have high blood pressure? If not, be careful standing up or moving too fast. You can get the room-zooms and pass out easily. The idea behind Nortriptyline is to keep your blood pressure from spiking when you have a migraine attack. I have very low blood pressure, and it was like my own personal amusement ride everytime I moved around, but then I figured anything that was that fun, couldn't be good for me, so I stopped. I couldn't every verify it did one bit of good for me when it came to my migraines. My last trip to the ER, my BP was 90/64. So much for spiking duing a migraine.
While food modification can be talked until death, I don't every remember seeing a fat jogger. You mentioned a gastric bypass, which if you are grossly overweight, is really something to consider, but must take into consideration not just all your health issues, but you lifestyle issues as well. I can discuss this topic from personal experience as well. I had a Roux-n-y Bypass four years ago this month. It can be a miracle or it can be a nightmare, or anywhere in between. You have to be clear on your expectations, and research as much as humanly possible on the subject, especially the clinics in you area conduction the procedure and whether or not they provide continuing care. I was initially very successful, losing 140 pounds, plus 180lbs(a husband), but I didn't get any of the built in negative side effects that are supposed to keep you from the wrong foods. Then I got put on DEPAKOTE, got major, certified eating disorders, and gained eighty pounds back. SO just beware.
I know you hate it when I end up talking about me, but one thing that might help with both the migraines and the physical issues is hydro-therapy. I have a really bad back, but things get better if I can spend a half hour, two or three days a week doing mild exercises in the family pool at the YMCA. In case you need swimwear, check out www.junonia.com.
Hope this helps and I didn't piss you off this time.