I called my doctor Monday, and he said that it was less serious than my mother had implied (mom's a nurse, for those of you who don't know) but still required investigation. I have an appointment with a cardiologist for next week Thursday for a Holter monitor (24 hour EKG monitoring for 1 day) and possibly an echocardiogram. In the meantime, I'm still losing weight, so that's a good thing.
I should talk about other stuff, but there's not much else to mention. Everything else that I feel like mentioning here is status quo.