im sorry for all the anxiety/ Depression youre going through. I have been there, done that. I dont know much about TMAU, read more around this forum though and you will find more people who will have experiences with this.
i THINK i remember reading about someone who actually found an MD that will test for this. Keep in mind though that TMAU is a VERY rare metabolic disorder.
Do you have any idea where your odor is coming from? if its from the armpits, try http://www.nomoreodor.com
and pay the $20, it will be well worth it.
in the mean time, try to hang in there - ive dealt with this for 10 years now, and if i can do it, surely you can