Hi loly and welcome.
I am in your same age range (will be 58 in June) and I also ended up about 20 lbs. heavier than I was at 9 months pregnant during any of my 3 pregnancies. This happened due to a medication I was put on but I was literally horrified....and stunned...that I could have possibly gotten to that weight. It was just way beyond any sort of extra weight I'd ever had to deal with or worry about. It was literally overwhelming.
But listen...you do NOT need to pay all sorts of expensive membership fees in order to follow a specific diet. There are all sorts of forums and threads here on a whole assortment of diets....all the ones out there, in fact. You can read around and find ones that seem like they could work for you and then join that particular forum or the threads for that plan. Plus, you can get all the support and help you need here that you'd have to pay for in order to get from these other places. And to boot, the people here are actually DOING the plan, not just selling it and/or advising on it....so IMO, the help and advice here is way better than what you'd have to pay for.
I'm also on the Atkins forum here (under low-carb plans) and also on the 50+ thread (under support forums).
deena