Well, I try not to be so picky about it and avoid it as much as I can. For example, in meat balls there's usually some onion pieces, so I just try to either "ignore" it somewhat, or if I just really feel it or see it I move it away.
I'd sometimes spend a few minutes just getting all the onion away and then eat :p
Luckily my family knows I hate onion, so they either not put it or just put big pieces so it will be easier for me to remove it :)
I don't like my dislike of course, it sucks hating onion so much, but what can I do...