Man, tough crowd...
Anyway, good of you to check with your AME. It doesn't fix everything, but it is helpful. Why? If the FAA does look into a hotline complaint, at the very least it doesn't look like you're hiding something, since you could report back that your AME did not think you had anything of note to report. Under the presumption that, if he thought you had psychosis or schizophrenia he/she would have assuredly mentioned it to you...
Having said that, the problem isn't really gone. I still agree with the other posters-if you can humble yourself and work it out with your ex GF, that is your best bet."Proving you're right" to your ex GF isn't a hill you want to die on.
If you can't be confident that she will not sent the FAA your screenshots no matter what you do, then you still have an issue.
Not so much that you will loose your medical forever, assuming you've been truthful in your history and no other medical, legal or other surprises.
The problem is analogous to you joking that you have a bomb in a TSA line. You can say "I was just kidding," but you're still going to get led down a different hallway than everyone else...
If the FAA gets a notification, they will likely ask for more information, and, probably, a more in depth evaluation. Why? Because they don't know or trust you. And, assuming there isn't anything you're not telling us, you probably will pass that evaluation. So I wouldn't catastrophize and assume your career would end.
But the question would be to see a HIMS AME now and get their input/eval or wait? The problem with waiting is that the timing could be very unfortunate. Say you do nothing, but she sends a screenshot to the FAA 3 months from now. Which just happens to be the time that you're applying to your dream pilot gig. It will take you months to clear that up, and you'll be under the FAA''s deadlines and/or have your medical suspended while your waiting and waiting for your evaluation and FAA review. You may get your medical back, but you lost your dream slot to your annoying rival CFI while this glacial process unfolds.
That's why it's reasonable to get a 30 minute consult with a HIMS AME and maybe an aviation lawyer. In the grand scheme of knowledge gained, it's worth spending that money for at least a one time consult opinion.