The reason you're gaining weight could be due to a combination of a number of different factors, including but not necessarily limited to diet, exercise and hormones.
I'd recommend getting a blood test done to analyze your hormone levels (testosterone, estrone, progesterone, DHEA, etc.) and see where they are as it relates to what it considered to be "normal ranges."
It's common for women over 35 to put on weight seemingly inexplicably, or find it more difficult to lose weight.
Sublingual HCG won't do much, IMO. That needs to be taken intra-muscular and is a banned substance in most places in the world.
Someone who knows a lot more about this than me wrote a really good article about it, and you can read it here: http://www.pamelaegan.com/weight-gain/
There's also a number of other articles on the site about hormone replacement therapy if you care to look around and browse the articles and the categories. IMO, it's a great resource about a lot of health topics. It's not a commercial site either, in case you were wondering.