Hello dear, thanks for your question on HCM. I can understand your situation and problem. Since you are having tachycardia (high pulse rate) , dizziness and chest tightness, better to rule out cardiac cause first. So get done ecg. If ecg is normal then no need to worry much for cardiac cause. Acute gastritis can be the cause for duch symptoms. Because nausea and chest tightness can be seen in this. And coffee actually worsens this condition. So you are having mostly acute gastritis. Better to avoid hot and spicy food. Avoid large meals, instead take frequent small meals. Avoid caffine containing drinks like coffee. Take Proton pump inhibitors. Don t worry, you will be alright.