Trouble getting along with coworker.

So, I've been at this job for a little over a year now and for the last 7 months, I've been having a really hard time getting along with a coworker of mine.

A little backstory, years ago I was diagnosed with TMAU, which for those who don't know, it's a genetic disorder that makes me smell really bad. I am not open about it, so to anyone who doesn't know me personally, I'm assuming almost always gets the impression that I'm just funky. Now, I have been able to mitigate my body odor very well, but the smell also lingers on my breath, despite my impeccable oral hygiene.

So, I when I started this job, the coworker that I'm having problems with was actually my trainer. She was a very good trainer, and seemed to handle the whole situation pretty well.

Fast forward to a few months ago, and I had a feeling that she may have been talking about me and my problem to our other coworkers. Maybe I was being suspicious, and it was all in my head because I was already feeling insecure about it, but I just had a bad feeling telling me that she was talking about me.

On her way out, she said goodnight to me and being childish I ignored her. This obviously angered her and fueled a 7 month cold war between us and everyone around us.

After this happened, she started asking me why customers seemed to ignore me. I would roll my eyes at her when she would say hi to me.. and now we basically mock each other.

I would have no problem cutting her off completely, as there is no real reason as to why I would need to talk to her, but she seems to really enjoy instigating things.

I have tried ignoring her, but she seems to always finds a way to be in my peripheral view, and "loves" to start a conversation with, and so it seems, about me..

This whole situation over what, looking back now, COULD have been nothing, or at least talked about and possibly diffused, has become something turbulent.

We have resorted to petulant, and petty tactics to hurt one another's feelings..

TL;DR: despite my great oral hygiene, I have horrible breath. Because of this, I had believed that one of my coworkers was talking about me, so I ignored her. She became enraged, and now we've resorted to petty and childish actions as a way to hurt each other.

Any idea on how to get past this issue? Thank you.