I'm not sure if it is age or what it is. After I had my last child at age 28 I packed on 30 lbs fast then had to diet for a few months to lose it. Then when I hit 38 I really started putting on weight and gained nearly 100 lbs after I quit smoking. Went to doctor because I could not lose it regardless of what I did. Found out I had underactvie thyroid. It has taken several years to lose 64 lbs and I still have another 30 or so to go but it is so slow.
So you might want to go to your doctor to rule out thyroid problems. Also do you take medications with prednisone in it.
Anyway I hope you can find all the help you need. I have found Spark People to be a great help with getting my calories tracked and motivation to keep exercising. I hope it works out for you too.
Happy New Year.