Wow, I can't believe families wouldn't be supportive. It's amazing how lax the world has gotten about that extra 20 lbs. I don't see anything wrong with wanting to be the size you want to be. You will be in better health. People think, "Oh, 20 lbs isn't going to cause health problems", but over time it will, or the 20 lbs will go up as a person gets older and soon it's 30 lbs.
My family is super supportive because we've all had issues with weight. My sister and my niece lost their weight, and I finally got tired of being the fat person in pictures, so decided to lose mine too. And they're calling me and telling me how proud they are, that they were getting worried for me because I used to be slim and they think it's great I am finally doing something for me.

Just remember that this weight loss is for you; it's for your health and your happiness. It took me a while to learn I have to change because I want the change, not because someone else wants me to change.

Good luck and just come here for support! It's the best thing I've ever run into on a search on the internet!!