I Am 75 Years Old, Used To Have High Acidity

I am 75 years old, used to have high acidity since I was 40. during the last two years within 10-20 m9nute after meal I feel pain cloe to the upper part of stomach close to the cardiac sphincter, sever chest pian which usually extend to the upper arms and in many cases the pain is accompanied by dizziness. This week, the dizziness was so sever that I fell on the ground. The bad thing I am a heavy regular smokers. Untill 3 months ago I used to smoke 40-50 cigarette a day. I was smoking since 1959. I am trying to top smoking - smoking between 6-10 cigarettes a day. Advice