Boob job

What are people's opinions on or experiences with breast augmentation? If you have it do you have silicone or the other? What is it like and what are the health risks? I've done research just want real peoples advice. I have an autoimmune disease that causes continuous weight loss and gain and the back and forth yoyo has really messed up my boobs and, although I never thought I'd see the day, I'm actually considering it now that mine look so bad at only the age of 21.