It takes two to succeed.
When they tell her she's never going to see you again, you need to know that she'll break down.
You need to know that she'll fight too.
Your fighting will look angry and defiant, and maybe emotional at times but not even close to enough to trigger change.
Because a sociopath would be just as angry and defiant, and that's what they think you are.
The difference (you know) is that a sociopath is reacting like that because they're not going to get their way - whereas an empath is reacting like that because a true connection - which is what they value above all else in the universe - is being severed for utterly wrong reasons and they're being painted as a sociopath and there's nothing they can do change it themselves. They see the suffering for both their soulmate and themselves and are desperate to relieve it but can't, and it breaks the heart and shatters the soul in a hundred ways.
Anyhow, your breakdown is simply not enough.
But if SHE breaks down and says she loves you too and begs and pleads and has the same reaction but charged with more "feminine" emotion, that tells them your feelings are in sync - something that can only be demonstrated, not proven with any logic no matter how correct it is - then that's when they will start to see what they're doing from a different perspective.
The perspective will be of an outsider to this inexplicable thing; whereas before, YOU were the outsider. Now, both you and SHE are the outsiders and therefore, from both of your perspectives: THEY are.
If this happens and yet the new perspective falls to willful ignorance, that's something of a mortal sin.
However, if this doesn't happen: that there wasn't enough there to justify the continuation of the thing in spite of the apparent social consequences is not a "wrong" position to take.
Not allowing her to know in the first place is just abuse though.