More loose skin after CO2 resurfacing?

I'm 26 yo. I've done 5 fractional CO2 laser treatments for my breasts (due to stretchmarks since puberty and loose skin after 40lbs weight loss) with intervals of 6 months. And I've seen a significant improvement. 3 months ago I did this procedure again in the other clinic. The doctor set very high parameters. So I still have dots all over my breasts, and it seems that I'm left with even more amount of loose skin, as if it aged a lot. Is it even possible? What can I do to improve this situation?