Spirit,
Sounds like you've had a rotten time. I do sympathise. There may be some areas that can be improved by exercise (buttock, tummy) but I cannot see how £60 in the bust area will help. Tightening the pec muscles won't help out there. Putting on topical creams will feel nice and make skin smooth and soft but there's damn little they can realistically do to firm/tighten skin. Think about it - if the creams were that effective, they would be covered in huge health warnings not to put near eyelids or mouth, for example. Imagine the effect of unintended firming/tightening?
When you think about it like that, it's more obvious that any creme you buy over the counter is really a placebo.
However, all is not lost. There might be something else that can help. Thermage or Pelleve Radio Frequency treatment works by heating the skin gently and it stimulates collegen production and that definitely tightens skin. I've had it done under my chin* after I lost weight and it worked really well, I'm very pleased with the effect. Extremely good result and it doesn't hurt and it's non-invasive.
The catch is: (a) you'd need to get it done every 12 to 18 months to keep up the effect and (b) it would be expensive for an area like the tummy, chest, etc. But it would definitely work. Much nicer than putting up with it, just a case of cost vs benefit.
- I also had the same treatment on jowls and whilst it was OK, it wasn't anywhere near as effective as on the chin.
The positive thing is that now you've lost the weight, in an less than ideal way, now you're starting to exercise, you'll be able to tone and firm up beautifully with targetted exercise. You'll be stronger and even though you'll still be slim, you'll be more shapely and therefore the skin (tightened or not) will be over a smoother, firmer base, as it were. So that's positive.
Finally - yes, sadly, the body produces less elastin, less collagen and less of lots of other handy things as time goes by. Irritatingly, apparently men keep elasticity and collagen levels for far longer than women, leading to the annoying situation where men of 45, for example, who do NOTHING with their skin looking firmer and more youthful than women of the same age who are very careful with their skin. Grrrrr. At least there are products that can help us, but no magic bullet alas.