Minoxidil and fast heart beat?

Hi , i Been using minixidil for a beard .I see Lot of videos where It realy help to grow beard so i decided to try it. I am 18 .So first time i take only 0.5ml in evening and soon after aplication i notice fast heart beat (i know it is side effect) i cant even sleep that night . I morning i take 1ml and fast hearts beat continue so i decided to stop using it .But 3 weeks later i was in the gym and after that i have very fast hearts beat for like 4 days .this never hapend to so please help