Welcome to the group. I have had weight problems my whole life. I can't remember how many times I have lost weight and regained more than I lost. I am counting calories and also doing intermittent fasting. I can only speak for myself, but this seems to have helped me alot. I saw something that showed no matter what kind of "diet" lifestyle you have, the key is to burn more that you take in. I am trying to have the mindset that I am not on a "diet" but this is my lifestyle I need to have in order to be successful. Good luck to you. There are all sorts of books about intermittent fasting.

I don't necessarily think that I have metabolism issues (other than being hypothyroid/treated), but I was able to lose weight at age 59-60, using MFP as a key tool. I don't really have the patience or inclination for structured or restrictive diets or eating programs, though I was willing to calorie count, so MFP was perfect. It seemed like a fun real-life science fair experiment for grown-ups, which appealed to my inner geek/nerd. 😉

It took a while to figure out the right calorie level to dial in sensibly gradual loss, and to figure out how to stay full, happy and well-nourished on those calories, but it was something I felt I could work at over a period of time and eventually "get there". That was 2015. I started with about the amount of weight to lose that you mention (50ish pounds), and reached that in just a bit under a year. Since, I've been maintaining my weight in a healthy range, without revisiting the obese weight I stayed at for around 3 decades, before 2015. I'm now 65, of course.

This pretty much describes how I did the "gradually remodel my eating" approach, and how I manage it in maintenance:

http://community.myfitnesspal.com/en/discussion/10636388/free-customized-personal-weight-loss-eating-plan-not-spam-or-mlm/p1

I think it was all a little easier for me because I'd been pretty active for quite a while, even while obese. While losing, I generally just kept up the routine of fun, active things I'd been doing, just making sure to account for them when estimating my daily calorie intake. I don't know how much it matters, but I was retired, too, at that point, so I had a little more control over my schedule than when I was younger and still working.

I think we have some advantages, losing weight at a little older age. Yeah, the habits we may need to change are a little more ingrained. But on the positive side, we have a lot of self knowledge (about our own preferences, strengths, limitations, and how to game them to achieve goals). We also have a lifetime of experience and skills for chipping away at big goals a tiny bit at a time, gained from things like getting an education, building a career, perhaps making a home and raising a family, possibly non-professional skills development like art/crafts/music, and more.

I'm not trying to say that weight loss or fitness improvement are easy (in psychological/practical ways) every single minute, but the basics are pretty simple, in terms of rules to follow: Figure out how many calories to eat to burn just a few more than we're eating, and do some fun activities that are progressively a little bit of a challenge.

Wishing you much success!