2yrs ago homocysteine level was 8 now it's 17.6!all other lab work is good.could it be a mistake?dr said to take trimethylglycine.thoughts?

Could be mistake but: Whenever a lab test does not make sense a mistake is possible, but it's equally possible the level of 8 from 2 years ago was a mistake! Get it retested; if still elevated I advise Methyl-Guard by Thorne or a similar product formulated to lower homocysteine. For a detailed discussion of homocysteine, how to lower it and why that's important see https://tinyurl.com/ycntmdgk