for 4 weeks now i have been suffering with a very fast heart beat, but i can feel it skipping and fluttering, i can feel it skipping through my chest . it mainly happens when im sat down resting (can be anytime of the day) but find it gets worst at night while im laying in bed. its very worrying i think my heart is going to stop at anytime. i also get hot and cold flushes, headaches , light headed, and everytime my period is due and when im on my period i get shortness of breath and its so scary. what do you think i could be suffering with?