HI, I have been using gaba to calm the glutamates. Can I get too much at night and it backfires? 2 different reactions---I can take one capsule it at 7:30 and I sometimes feel dowsly or no affects. other time is if I take it right when I hit the pillow, it seems to wake be up and my heart seems to race. I can't seem to pin it to anything else I am taking. Any ideas?