Firstly,it's not my first clen cycle. I've been running clen for 3 days at 40mcg,then on 3rd day at night I felt my heart was pumping,I felt that I hit a pretty high heartbeat,so I popped a tab of ketotifen and then seconds later my heartbeat has increased and then muscle crumps/shakes started all over my whole body,intense shaking,like I'm nude in Alaska.. I have never experienced anything like this before,what this might be ?