In addition, I would suggest a couple of cosmetic counter things that have given me some limited help. (BTW, I have aging skin so I understand about the loss of collagen!)
If you have indentations in your sking, try one of the products made for "emergency hydration" of skin. They are the kind of thing that's often used by people after a night of serious partying. Not exactly our cases with apnea treatment, but..... Anyhow, I've tried a couple of samples of that kind of thing and they do seem to lessen the creases caused by straps. Your local Sephora store or the cosmetics counters at a big department store might be able to steer you to something that works with your skin. You can also look for products with ceramides and hyaluronic acid: they work fast. Basically, you're trying to get water into cells so that everything will plump up again. Pressing a warm wet cloth against the face can also be helpful.
If the problem is more because there's swelling along the places where a tight strap has pressed into the skin, I would suggest using something like what is used to bring down the undereye swelling caused by allergies. There are lots of products aimed at this market, as those undereye bags are really unattractive. Kiehl's makes one that's full of caffeine and does quite a decent job of tightening things up.
For a truly desperate ritual, plump up the strap tracks and chill out the swelling along the side of the tracks.
None of this will do miracles but it can speed recovery up so that you are more presentable when you have to face the world.
This is where a world of face masks can be a real help!
