Don't know what the heck a "diagnostician" is. See a good psychiatrist for a consultation. I took tricyclic antidepressants many years ago for severe muscle pain from fibromyalgia, and gained an absolutely amazing amount of weight which I am still trying to get rid of. To test that the weight gain was from the antidepressant, I spent a month dieting quite seriously at 900 calories a day and taking four ballet classes a week, and at the end of the month had still gained a pound. Those drugs can definitely cause dramatic weight gain all by themselves.
"My predominant feeling is one of gratitude. I have loved and been loved;I have been given much and I have given something in return...Above all, I have been a sentient being, a thinking animal, on this beautiful planet, and that in itself has been an enormous privilege and an adventure." O. Sacks