Around 6 months ago I started supplementing with something that was causing an extreme die off. It was similar to when i first started but the die off was much worse, I had the same feeling in my chest and was coughing for about 3 weeks. It was weird cause I felt sick and started to feel really good at the same time like getting more energy. I just drank a good amount of water, used a vaporizer when I slept . You should grab an anti-oxidant, a sea salt water flush in luke warm water may help if you do it every couple of days. If you feel up to it try going for a run, sweating some of it wouldn’t hurt.