We understand your concern
Definitely you should stop smoking. Churchill once said "It is very easy to quit smoking, in fact I did it several times". In your case, you should stop it once for all because you are worried about your health which could later lead to depression
and further. You stopped it successfully for a year or so.
Secondly your body is very efficient to adjust and repair itself from the ill effects of smoking
, May be 1 year max.
Get well soon.