It's got to be your hormones. I'm 43, and some days I wake up looking like me, and others I wake up looking like a purse. It depends on what I've been doing the day(s) before.
I also used to have acne prone skin. The first thing to do is stop using the acne washes. They are so drying that they can actually make acne worse. Nutragena has a 5% benzyole (sp) peroxide cream you can use for spot prevention, and then there's always Clearasil when you need the "big guns". I use the Olay line because all of my "older" friends raved about it, and it does do the trick. I switched from Cetaphil because I found it too drying. I did a lot of reading about what to choose as well, and the more expensive lines didn't perform any better, but they did tend to have a nicer fragrance (if you want that). The same is true for sunscreens. Speaking of sunscreen, I use Clinique on my face and neck. I wouldn't recommend this for summer, but in the WINTER you might want to try a hyloronic(sp) acid. It will help remove dead skin, keep blemishes at bay, and moisturize, too. Since it exposes new skin, it's not a great idea for summer. Even with sunscreen, you're bound to get exposure.
As for preventing the dryness and restoring some moisture, the only thing I would add to all the great advice you've received is to avoid alcohol and salt, and get plenty of rest. (For some, that's impossible!) The thing is, your skin will only quietly trill, "I'm lovely!" when you do things right. It's when you DON'T take care of yourself that it screams and is noticeable to others. Also, if you sleep with a ceiling fan blowing on you, it might be time to look for an alternative. There's only just so much even a heavy night cream can do, and you don't want to wear so much that half of it ends up on your pillow. Lastly, sorry for the spelling errors - I have small children, and I had to rush through this! Best wishes!