I think slowing it down is a good idea, to give your body time to adjust to your positive changes.
I have a friend who had a similar situation and she ended up having a surgery to get her excess skin removed/repair her breasts.
Without personal experience with the issue, I don't make any recommendations concerning what do to for sagging skin--but I will suggest that if you want to continue to lose the weight, lose the weight. Then once you are where you want to be, if there is still something going on with your skin that bothers you, deal with it then.
Do one thing at a time, and as you obviously have some great momentum with your weight loss, follow it through to its logical conclusion, because that's what you wanted. And be encouraged that you're beautiful regardless.