Also not sure if it related but since quiting also for the past 5 days I have had tonsillitis. And it has been the worst I have ever had it.
Most people have a constant chest infection when they smoke, but it's just kept at bay underneath a layer of tar.
When you stop smoking, you stop adding to the layer of tar, slowly it breaks away.
This means sometimes you will cough up bits of black, and eventually when the infection surfaces you get a full on chest/throat infection.
Don't be surprised if you start coughing up blood

I quit smoking for a year, it was 3 months before I went to uni. After a year I had put on 6 stone!
Most people put on weight at uni and after smoking, and the two mixed together didn't help.
I've now been smoking again for a year and a half and I love it.
Tempted to get the e-cigarettes for when I leave uni and go into the big bad world.