hey, I've been suffering with the symptoms of TMAU since I turned 18,(9yrs)

sometimes it is a fishy odour but mainly 1of poo, smelly feet and bad breath. I plucked up the courage to tell my gp a few years ago about these and was told he couldn't smell anything and that it was in my head, also the reaction of my family. I can only smell it sometimes as my nose seems to be blocked alot. But the amount of comments and hurtful remarks I recieve, I know I smell!!! I have been given a new gp and after researching
symptoms I'm positive that I have TMAU and have asked to be tested. My gp gave me a blank look when I asked and I seemed to know more on the subject than he did!He googled TMAU and I've given a urine sample but he seemed at a loss as to where to send it to. i.e which lab? Does anyone know where or if I can be tested in the N.W (u.k).
Also I'm a heavy smoker, I read somewhere that this can make symptoms worse, Is this true??
Thanks Neil