Protriptyline??

Hi there,
I am thinking of asking my neurologist about trying protriptyline. This is because ?I have been using amitriptyline successfully to treat chronic migraine for the past 6 months or so.It helped me sleep better and improved my moods. My only issue with it-- which my mow FORMER neurologist never warned me about, was the TREMENDOUS CRAVING FOR SWEETS AND MASSIVE WEIGHT GAIN. At first I didn't even notice. But when I started substituting healthy meals for cake and pasties, I decided to google amitriptyline and sugar cravings-- only to discover that it is a well known side effect of this medication. I've gained almost 40 pounds and they just keep on coming. My metabolism has changed-- I wake up starving in the middle of the night if I don't OVER eat. It's horrible!! So I'm hoping that since protriptyline tends to help people LOSE weight, helps with mood and chronic migraine, that it will be a good substitution for me. I've tried Topamax ( made me STOOOOOPID!!!) and I am currently taking 240mg of Propanolol daily. I have to take propanolol plus one more preventative for things to be under control, but they are. I just don't want to risk diabetes, heart disease due to weight gain. I've already noticed an unhealthy increase in my BP.
Please share your experiences! Thank you!