I am sorry to hear what you are going through, however, you have taken the correct step in trying to find out more about your odour problem and you will discover you are certainly not alone - you can get plenty of advice and support on this site, and you should also try other sites just google the titles:
'Bloodborne Body Odor and Halitosis',
' Body Odor Support',
'People are Allergic to me (PATM)'
You mention that have read about Trimethylaminuria (TMAU for short). There are two types of TMAU, type TMAU1 is a genetic form when someone is born with a defect in their enzyme FM03. They normally have a fishy smell which changes with their diet, and other smells are released which vary from garbage, seweage, sulphur, faeces - it depends on the food they eat and how their body deals with it. It is normally sporadic and they cannot smell it, and their family usually cannot smell it either.
The other type is TMAU2, which is an acquired form. By this I mean some trigger blocks the enzyme FM03 from working properly. This could be a hormonal problem such as puberty, or it could be due to a liver problem, or it can be due to a chronic infection somewhere in the body - generally a gut dysbiosis. A gut dysbiosis can be bacteria and/or candida somewhere in the intestines, usually but not always the small intestine.
Before the odour began, did you have to take a course of Antibiotics , steroids or something similar? Was your diet very heavy on carbohydrates? Did you have gastric problems, constipation etc? Basically anythings can cause an imbalance in your intestines and this creates a dysbiosis. Another question - is the odour definitely coming from your whole body? Some people have found they have had a tear, cut in their back passage possibly due to straining during a bowel movement, and this caused their problem.
Tests are available for both TMAU1 and TMAU1 in some countries, but others only test for TMAU1.
You do not say if you have been to your GP, or have you discussed any type of testing with your family? For info, there is a post on about a guy who suddenly developed an odour similar to yours, and he discovered it was due to an overgrowth of candida - so it would be worth getting tested for this. You could ask your GP for a hydrogen breath test, which will let you know if you have a gut dusbiosis, and you should definitely ask about testing for TMAU.
In the interim you will need to change your diet. You should try the low choline diet, and you should read Maria's post on how her son cured his fecal body odour. She explains his diet. You could discuss this with your family and GP.
Hope this helps. Do not get disheartened, stay strong - I hope the diet helps you.