I'm sorry you have had to deal with all of these terrible things, both the recent and during your youth.
Since my teenage years, I gain weight when I am depressed and then slowly lose the weight, get healthier, when not depressed. It is hard to lose weight when you are depressed. And it sure does sound like your weight problems have a psychological component so I think that if you can continue to go to a psychologist plus go to therapy, it will help with your physical health as well. There is certainly a mind/body connection. In addition to my mental issues (MI) causing me weight problems, it can make my blood pressure go up. Funny how therapy, not blood pressure medicine, helped me bring my blood pressure back to normal.
I have also been prescribed Welbutrin and notice it helps with both the "blues" and helps me lose weight. I was once prescribed 300 mg daily and found that dosage gave me anxiety (only took that much for four days) but have taken either 200 mg daily or 150 mg daily for the past 4 years. I currently take 150 mg daily. Maybe consider taking this medication again? It sounds like it has helped you too.
That all being said, all the recent events have thrown you for a loop so it is probably going to take time to get unstuck. I know it is hard, but try not to hate yourself--you sound amazingly stable given all that you have gone through. Take it one day at a time, try to eat a lot of vegtables and walk daily. Remember, when these things happen, it takes time to heal. Plus keep posting. I am also trying to lose weight but it is so hard during the month of December. So we also have that to contend with as well.