At 51 years old I imagine that @AppleDumplings is very much like me in this regard. We absolutely know what we should be eating. I think that both the OP and I could write an up to date version for the NHS of how much of any of the food groups we should all be* *eating, paying particular attention to our lifestyles, including our weights, heights, fitness levels, ability or desire to exercise, and if we enjoy exercising what types we do, or would commit to doing, regularly.
My problem is that having spent almost a lifetime on starting diets, and even having twice lost a considerable amount of weight, I am totally bored of trying to eat the right things - and consistently failing in the long term. I also have an underactive thyroid and am on HRT. My body does not want to go below a size 12, when it has I have looked gaunt and not felt well. However, I now weigh significantly more than the OP, have type 11 Diabetes, am both very depressed and stressed, and am taking opiates (legally prescribed) for severe pain caused by various other conditions. I would love to weigh less, and be a lot slimmer, but I am too tired, too miserable, and too lacking in any enthusiasm to put myself through the agony of constantly trying to lose weight and be healthy, to diet any more.
Sorry @AppleDumplings, I am sure that I'm not helping you, unless you can get some motivation from my failures, to help you make a determined effort to not turn out like me - I am over 10 years older than you, you do still have time to turn your life around. Of course your underactive thyroid, peri or actual menopause, and your HRT won't be making life any easier for you either.
By the way, I would love to be a size 16 again, but I just haven't got the energy or wherewithal to even attempt that anymore.
If at all possible OP, please have another go at changing your whole lifestyle quite dramatically, or just accept you will be a little overweight, but not morbidly obese like me. Just don't spend the rest of your life feeling like a failure. I am sure that you will get some good tips on how to change your frame of mind, you certainly don't need tips on what you should or shouldn't be eating! 💐