I ve gotten heart burn for a few years, it was always very mild and very rare, but in the last w/o months it has spiked dramatically, to the point I get it at least 3 to 4 times a week. It hurts, makes me nauseous, it sometimes gets hard to swallow, makes me feel like I m going to vomit, and sometimes feels like something is stuck in my throat. What could be causing this?