I wonder if it's an opportunity to share something that may help her?
In general, no. It would be very difficult to hear you have a mental illness, for anyone, and it wouldn't help coming from you anyway, since you broke up and you are no longer the soother, you're the trigger. Better to look at your motivations for trying to help her, I understand the impulse, although in the context of a failed relationship it's really no longer any of your business. Going from a sliver of hope to no hope at all is a huge leap, one we all take eventually; what's the main reason you want to help her?