Hoping to be a brand new me!

I have tried Weight Watchers countless times, also Nutrisystem and Jenny Craig... now I'm in my 40's and my metabolism has slowed down to a crawl. So, my doctor told me to try My Fitness Pal, so here I am! So far, I like it, and best of all it's free! I was paying for Weight Watchers online and this is just as good!! Any one who can give me some encouragement, please send it my way as well as positive thoughts!