Well, it actually is true that low estrogen levels do cause aging of skin. But that is more like after you go through menopause (and while you are getting older when you have that, the reason we know that estrogen plays a role is that when a younger woman has a hysterectomy they are thrown into full menopause right away with a dramatic decrease in estrogen and their skin will show effects right away . . . IE: my sister in law. ) However, you probably wouldn't have your estrogen dip so low to have this situation from discontinuing breast feeding. Night sweats can be an effect of changing hormones and also happens when estrogen levels drop. But all of this is pretty dramatic and unlikely at your age and from just discontinuing breast feeding. What I'd do if I were you is to see your ob/gyn and get your blood drawn to check hormone levels. They can then determine if you really are low estrogen. And if it is so low that you have these types of issues, then you can perhaps take BC with estrogen and bump back up to get regulated again. I had the opposite for a good while of TOO much production of estrogen which acted like a natural birth control pill, infrequent periods, melisma on the face (lovely), etc. That was a bummer. But definitely, out of nowhere, hormones can get out of whack. My estrogen righted itself without intervention but sometimes there is some needed. When at the doctor to talk about your hormones, talk about your PDD too. Having imbalanced hormones would compound that problem. Do you take anything or do anything for the PDD? Let us know what the doctor discovers from blood work to check your hormones. I'd love for you to come back and update us!
I am not sure what you are describing comes from low estrogen levels. The wrinkles sound more like dehydration from the night sweats. Talk to your doctor and get some blood drawn and see what is going on with your hormone levels, don't let him or her fob you off with "it's normal." Be sure you are taking all your vitamins, as many as when you were pregnant or more, including iron especially. And get over to your doc! Good luck.