Have I seriously damaged myself by an dangerously unhealthy past lifestyle?

I have smoked about 60 a day from 14 - 30, I took large amounts of amphetamines daily for coupla years in my early 20s and was very underweight at that time. I then stopped those but overate loads ( Was nearly 20stone or 270 lbs) and drank lots of wine (about three bottles a night) for 5 years. I stopped the drinking, drugs, smoking and eat healthily, maintain a healthy weight and do lots of exercise for the past 5 years. I'm 35. Can that have repaired my body totally or am I gonna have a reckoning sometime soon cos my body thinks its 80? I have a pulse rate which drops to 40 frequently and makes me faint - I have terrible headaches, sickness, dizziness which, like the heartrate, is controlled well by meds.Before that I went cross eyed for a few months for some reason no-one could determine. The various consultants have said my pulse rate is low cos I'm fit and the other symptoms caused by a typical migraine disorder but I haven't mentioned the drugs. Wondering what I've done to myself.