your doc is just being cautious. Very good idea to start out slow. I increased far too quick in the first week and ended up feeling worse during this time. I got up to 75mg in the first 2 weeks which is far too quick but the transition after this time was almost magical.
I hit the euphoric period and felt absolutely awesome for about 2 - 3 weeks after this initial time. I got the full body pleasure feelings, and I remember particularly that sleep and resting was the best feeling I ever experienced. I'm a smoker and everytime I had one it filled me with a huge dopamine rush that was pure bliss (not that I recommend smoking).
I happened to be on holidays for a week during this euphoric time, and I remember after a big night of drinking (which felt awesome by the way) I was lying on the beach and felt the best I have in my life. I drank pretty much every night and had no hang overs at all, just felt extremely good the next day.
Anyway, my rant is over, but I think the sun and exercise helped the nardil get into my system better so make sure you get plenty of both, and good luck!