research everything you can...online...talk to a dr....come here and read, read, read!
WLS is not a magic pill, it doesn't fix the brain and the reasons I ate in the first place...it just makes the stomach smaller...you still have to diet and exercise! It's NOT fail safe.
You could speak to a counselor and see if you can resolve some of the emotional issues that might have contributed to the weight gain (if there are any). It's a tool, like running, that helped me to change years of bad choices.
I don't recommend surgery to anyone...it's a life changing decision. But I will say, you have more then just knee surgery that would qualify you for WLS. The blood pressure issue you're having is also what they call a co-morbidity.
You may have a hard time finding a doctor that will do the surgery on such a young person (there are some that refuse to) and though pregnancy is NOT recommended for at least a year after surgery (because of the food restriction in the months following say...Gastric Bypass) you can, down the line, safely get pregnant as long as there are no complications to the surgery...Or so my surgeon said before I had my GBP.
If you seriously decide that this is the route you want to take, this IS, most definitely, the forum for these kinds of questions!
Good luck honey,
Angela