Weird feeling in chest when I laugh or cough

I’ve been having this weird feeling for a year now, when I laugh, cough or bend down I feel like my heart stops and I lose my breathe for a second. I’ve had a chest X-ray, endoscopy, blood tests, ekg, tested for a blood clot, they can’t find anything but a hiatal hernia. Has anyone else ever experienced this? Is it the hiatal hernia moving?