TM,
You are such an incredibly beautiful person. You are not ugly, fat, or hopeless and I'm sorry you are feeling that way. A person as beautiful as you on the inside cannot be ugly or hopeless. Many people have weight they want/need to lose. I'm sorry you are in such pain with your back. been there done that, and it is no fun.
One thing I love about ww is that everyone there is in the same boat. We all struggle with our weight. Every employee has to have lost weight through the weight watcher program before they can work for ww. I found the support at meetings so helpful and hope I'm helping those I weigh in now.
I also think the ww program is a really healthy program and I like it because you choose what to eat! For me a program, where I could make my own food was essential-I enjoy cooking and also don't want someone telling me that I can't eat something.
As for feeling awkward at a health club or in classes, many have classes for beginners. Water aerobics is also a great place to start because of the no impact. If you don't like classes, what about just biking. Do you have a club around you that has all sorts working out? I know I have been glad my club has every body type, shape,age group, etc...