Hey.
Well, it's nice that you're honest about what you are and are not.
It sounds like you're pretty depressed, and so I don't want to kill any hopes you have, but the fact is to achieve what you want, you are going to have to commit to making a big change or two in your life.
I too did Atkins about 10 years ago, dropped 60 pounds in 6 months. And have never gained it back, but, I am very active. I hate to say it but there's no magic way to drop the weight you need to.
Aside from being active, you need to understand, it will take a long time to drop that weight. Even on Atkins, which obviously did work for you when you followed it - you're probably looking at a year to really do it properly and healthily (please no discussions on if Atkins is healthy or not).
What I'm trying to say is.
You are 38 now. It took you a long time to get to 38. And if you stand back and look at it - devoting a year of your life to work hard and drop the weight - it's not that long. Before you know it you'll be 39 looking back wondering how you got there so fast.
I'm a huge advocate of exercise and have been active for my entire life. So, instead of giving you a typical beginner pep talk like hey just start walking or riding a bike etc etc....
I'm wondering if you know anyone who you could talk to about this, a peer, who might also be willing to start doing active things with you. Many of the people I meet who aren't active, it's because they don't know anyone else to be active with and they get bored or discouraged doing it on their own.
You need someone to motivate you. And if you could be blunt with someone, tell them plain and simple you want to lose xx pounds of fat, you're tired of it and need it for a surgery - and ask them to help motivate you.
Easier said than done I know. But you need to make a change in your brain, to make a change in your body. And I think coming here is a good start.
Good luck.