Hello and thank you for using HCM.I carefully read your question and I understand your concern.I will try to explain you something and give you my opinion. You should know that fluttering sensation are related to rhythm issue.There are some electrical impulses that generates from parts of the heart different from normal sinus rhythm.They cause premature heart contaction and you feel like esceped beats, fllutering sensation.You might also experience lighthead, difficulties in breathing deeply. The causes of this rhythm issue might be different to emotional stress, coffee or energy drink consumption, patologyes like anemia, hyperthyroidism, electrolyte imbalances, active infections ect. The fact that you are diagnosed with a sinus infection might be responsible for your head ache.An active infection in the organism might be the reason of the rhythm issue and related symtoms. So, if I was your treating doctor I will recommend some examination like a cardiac echo to evaluate heart function and walls, a full blood analyze to exclude anemia , hyperthyroidism , electrolyte imbalances and of course a holter rhythm monitoring to evaluate your rhythm tendency After all this we can better judge what we are dealling whith and how to treat it. Hope I was helpfull. Best regards, Dr.Ervina.