I've done a lot of research on raw foods, and it seems the best way to go, healthy or not, overweight or not. From what I know about raw foods (I have yet to adopt it myself, so I can't speak firsthand), people's bodies heal themselves from years of damage. Fasting can do that too, but raw will help you continue to cleanse your body, and you'll repair anything that needs to be repaired. If your metabolism is too high or too low, it will even out. If you need to lose weight, you will lose it, and you won't have to try. Your body will improve, your skin and hair will improve, your mood will improve, your health will improve. It's an all around winning situation.
I don't want to be over the top about this, but going raw can cure things that doctors would prescribe dangerous drugs for, or that they would recommend surgery for. People have even had cavities reverse themselves. Your body is your best defense against old age, disease, and weight problems. If you give it fuel instead of junk it can't use, or has to work hard to digest, it will be able to focus on taking care of itself.
You can eat some meats with a raw lifestyle, but you have to be careful. Ideally, vegetarianism is pretty much considered the best lifestyle by alternative practitioners, but if you can't do without meat, there are still ways to enjoy it. Even going 75% raw will help a lot. I've also read that
juicing your vegetables is better for you, because they're much easier to digest that way, and eating fruits whole is better, for the fiber, and because they digest more easily. Organic is obviously preferable.
I don't know what the cause of your inability to lose weight is, but the weight gain is a symptom of a problem, not the problem itself (which you already know). You may be right, and you may have screwed up your metabolism, but I've spent years yo-yo dieting, and have been "almost" anorexic at times, and then have gone from that to bingeing, and my metabolism is still okay. I'm fasting right now, and am losing normally. Your age could be a big factor. Maybe you should try some other exercise instead of running. Your body might be too used to the routine. Try circuit training, spinning, elliptical, or aerobics. I love pilates.
Another thought is that you might look up a natural health practitioner. They might be able to pinpoint something that a doctor would miss, or misdiagnose. I'd always make the doctor your last stop. There are so many other ways to help yourself.
I don't mean to preach. I myself need to listen to my own words, because I've got horrible eating habits. I do know that going raw will help anyone, and I plan to go raw after my fast. I have done it for short periods of time (like a few days or a week) and did feel better, cleaner, and more optimistic, and that was just after a few days. Just suggestions here. In the end, you should do what you feel comfortable doing. I really hope you figure out what the problem is.
Anyway, good luck to you!