That's a fantastic achievement, well done! At my top weight (before SW) I was 17 st 9lb and so I too am having skin problems!
The sad thing is that if the sking has lost all elasticity it can't bounce back, however there are things that can be done to improve the look of it.
For your arms, tricep exercises. I bought dumbells, just the foam type ones and do these every night. If you build your triceps the skin can cling to the muscle, therefore reducing the flappiness. I think mine are improving.
Stomach, you need to ab crunches, etc for the same reason, the skin will cling to the muscle. This alos applies to the thighs. I just googled exercises to find ones that would suit me.
As for the breasts, I've tried every exercise under the sun and miracle creams and I'm afraid it's just not going to work!
Have you spoke to your G.P? They can refer you for lifts, tummy tucks, etc if they feel you are a suitable candidate. To have any of the ops I believe you have to have a BMI of under 25, but this varies from PCT to PCT.
I have just been referred for a breast lift and am awaiting a consultation date. It's a long process though. First you see a plastic surgeon and if they think you are suitable you then have to see a psychologist who judges whether or not it is affecting your physical and mental health enough to warrant the NHS paying for it. I am trying not to get my hopes up, but I reallly want it done!!
Hope this helps, and keep your chin up
K xx