Yes cosmetic plastic surgery can be used for skin firming and loosing flab ( in the form of liposuction) as well. But they should be got done from a good plastic surgeon.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.