If you quit now, you will be healthier than if you didn't.
Generally they say that the amount of pack-years you smoked is the amount of time it takes your body to completely recover. So theoretically If you smoked a pack a day for 35 years then quit, in another 35 years you'll be as good off as someone who never smoked.
in reality there has probably been permanent damage to your lungs, heart and vascular system, and brain. But quitting is always worth it
Quitting is always worth it
I'm not exactly what you mean by saying, "Will I be OK?", but I do know this ... quitting at ANY age, after how ever many years is a good move. I admire you wanting to quit. I am 47 and have been smoking since I was 20. I want to quit too!!