I got drunk and stupidly used meth one time last weekend. It was wacky and I'm not going back there but I just found out I can get a job if I do hair follicle testing this coming week... I used about .2 of a gram... Will I fail the test... And if the test is positive will the reading be super high?

How do you know it was .2 of a gram? Its seems really odd since if it was only a one time use... and people generally as a rule don't out of the blue go from no drug use of any kind straight to meth (and a first time user wouldn't be weighing it out), you would be an exception to the rule when it comes to meth if that is really true.

The lab results will be whatever the lab results will be. They can't be fudged. And it will know if there was a one time use or if it was really more or included other types.

For a hair follicle test, you should be concerned with the past ~3 months of drug use. Single use a week prior would probably not show, given that 1) your hair doesn't grow that fast, the HFTs I have had, they use clean scissors and snip off the hair, leaving about the past 1/16th" - 1/8th" on the scalp and 2) one time use is unlikely to show up on a test that is intended to show use over time.

If that is the only illegal drug, including prescription drugs not belonging to you that you have ever done, I wouldn't worry at all. If there is more to the story, then all bets are off.