As others will say, keep seeing a doctor instead of the internet but...
It may be worth a small investment in a AliveCor KardiaMobile 6L or a similar device. Then you can take your own EKGs at home and possibly catch something that is intermittent. There are certain heart issues like a Left Bundle Branch Block (LBBB) that will cause the device to be unable to classify an issue but at least you'll have a history of EKGs to show your doctor at your next visit.