[mtalantikite]

I've heard about a similar thing happening to someone on a Goenka Vipassana retreat. The sound from their heartbeat became too overwhelming for them and they had to stop.

Maybe taking refuge in the impermanence of that feeling could help? That the squeamishness is just a state of mind and like all things arises from emptiness (sunyata) and returns to it? But yeah, putting away the practice sounds completely reasonable in this case.

In a Thai tradition I practiced a bit from they'd tell you to not focus your attention and awareness on anything above the heart center at the beginning, to really just keep it at the naval, as these sorts of difficulties with the body aren't uncommon.