Thanks for your question on Health Care Magic.
I can understand your situation and problem.
Since you are smoker and having slightly elevated
heart rate and blood pressure, better to get done 2d echo and
stress test (trade mill test) to rule out heart diseases.
If both these are normal than no need to worry for heart diseases.
Smokers are known to have gastritis and
acid reflux.
Both of these cause nausea and central
chest pain.
So first of all quit smoking as soon as possible. It is the main cause for your symptoms.
Then take
proton pump inhibitors for gastritis.
Avoid stress and tension. Avoid hot and spicy food. Avoid junk food.
Don't worry, you will be alright.
Hope I have solved your query.
Wish you good health. Thanks.