Welcome to SR!
The worst of the withdrawals will most likely resolve after two weeks at the latest. Getting back to normal though...that's a tough question. I've heard up to 6 months isn't unheard of to get your body and mind completely back. You're young though, so you will probably bounce back a bit quicker than a lot of people. I'm at 7 weeks myself, and I still have functionality issues with my head.
Distraction is a good idea. Good for you. Anything you can do that will both distract you and help your health is a good idea; to that end I would recommend lots of exercise. A gym membership is good so long as you have the discipline to go there. And, of course, you obviously have the internet, and there's no end to distractions there. I spent a lot of my first few days curled up and watching YouTube.