That doesnt sound too good at all. Its funny you say that about the effects of taking single aminos. L-glutamine was amazing for me when I first took it, energy out of nowhere. But the effects bottomed out after about a week and I was left with a horrible hangover like effect for two weeks straight. Great stuff if you can tolerate it but like you said, caution should be exercized. Methionine had a similar effect on me also