from your history it looks as if you are having periodic episodes of Atrial Fibrillation
also causes palpitations at times , but in your case it is Atrial fibrillation which needs detail evaluation .
You must have cardiologist opinion at earliest .
Consider 1 Holter monitoring to record event of AF
2 also electrophysiological studies ( EP study ) will be required after initial evaluation .
Present line of treatment is right but can be modified after further evaluation .