Why do i smell like onions and butt?

Okay guys,, i am 15 years old and i suddenly smell like onion.. only in school but i never smell like onion outside the school like if i hang out , chill bla blaa ,, i really don't know what to do :( i feel really bad because i am clean and i shower daily and when i smell like that i feel there is something wrong,, here what i did

i change my diet

i change my underarm deodorant

i change my shampoo

i change my body shower gel

i bought hugo boss

i bought new shower loufa

and i still suffer from this smell :( just everytime in class if they say smells like onion here or they keep sniffing that really hurts me :( i need help please! i went to a doctor and she told me if u want make blood test okay,, but there is no such thing as onion smell from blood test so she didn't help me at all :( and last thing when i rub my hand by any metal or aluminum surface my hand smell like onion. i shower in morning before i go school ,, hope anyone here can help me as soon as possible :'( i can't even talk to my best friends or do work in the class

Additional Details

i don't eat onions or garlic i don't like them =[ it's very weird that i can't even understand what is happening that when i ask my parents or trust friends they say no smell man,, idk what to do,, that happened to me for the very very first time and i shave my armpits everything before it even grow,, i just feel bad because idk what part in my body smells,, armpit or hair or idk i am so confussed i really need help :(

i been clean the whole school year,, it just suddenly came like 2 weeks ago and idk the source,, idk what else 2 do ,, i have like tried everything even i made lemon juice and i shower with it,, i bought brand new clothe and try them still the smell here... i just don't get it =[

Hope i find a cure before it get worse =( i really need help please :'( i just can't take it anymore,,