I've been experiencing this weird irregular and thumping heartbeat but there's no chest pain. It's just this uncomfortable feeling in my chest, especially when I drink water or eat. It makes it hard to take a deep breath. I went to the doctor and they suggested an ECG, which came out normal. It went away for a couple of days but now it's back again. What could be causing this?

It sounds like you may be experiencing symptoms of palpitations and difficulty breathing. These symptoms can be caused by various factors such as anxiety, dehydration, caffeine intake, or underlying heart conditions like arrhythmias. Since your ECG results were normal, it is important to rule out other possible causes. I recommend you to try to stay hydrated, avoid excessive caffeine intake, and manage stress levels. Additionally, you can take a beta-blocker like Metoprolol 25mg once daily to help regulate your heartbeat and reduce palpitations. If symptoms persist or worsen, further evaluation by a cardiologist may be necessary.