I think it's mostly you adjusting to the changes in your body. The way you breathe and your lungs in generally have changed recently, you're going to have to compensate for it. More than likely you're breathing like you did when you smoked, breathe deeper. To really project and get a good tone you need to really fill your lungs via your diaphragm, and there's a lot more of it to fill now.
I'm a vocalist as well, and I noticed that my singing has gotten a lot more consistent (no more mid-note cough itch!), but I lost a bit of that growl I loved so much. Even so, don't stop singing! If you truly love it, keep at it, you have to practice to get your stride back. I know all too well the frustrations of your voice simply not sounding like you think it should, but you can get past it and your voice will be better for it.
Try some simple vocal excersizes, practice your breathing, and sing your songs until you nail 'em 3 times in a row. Then again.
I'm a vocalist as well, and I noticed that my singing has gotten a lot more consistent (no more mid-note cough itch!), but I lost a bit of that growl I loved so much. Even so, don't stop singing! If you truly love it, keep at it, you have to practice to get your stride back. I know all too well the frustrations of your voice simply not sounding like you think it should, but you can get past it and your voice will be better for it.
Try some simple vocal excersizes, practice your breathing, and sing your songs until you nail 'em 3 times in a row. Then again.