<human>: Condense the text into a few key points

I identify as asexual/aromantic and have since I learned what those terms were (about 5 years now).  I am not officially "out" to anyone besides my best friend [19F].  About a year ago, I told my mom that I believed I was asexual, and she did not seem to believe that was an actual orientation but that I had not found the right person yet.

Three days ago, I was invited (via Facebook) to an event at my college that was a panel on asexuality/aromanticism. I checked the box that I may attend, and then forgot about the panel as I became super busy (yay midterms!).  The event was about three hours ago.  One hour ago, I received an email from my mom with a snapshot of the event asking what it was (though the email could have been from my dad as they share a fb account and he occasionally uses her email).  If the email was from my mom, my dad will no doubt be seeing it at some point.  And knowing them, my siblings [15F/10M] will probably find out soon.  At this point I have no idea how to respond or what to say.

I had been planning on coming out to them both when I went home in December, but right now, I have no idea what to say.  At this point, I am freaking out because this was not how I wanted any sort of convo to go.  I have no idea what to do at this point.
<bot>: I may have outed myself as ace to my parents via Facebook, and my mom sent me an email asking about the event.  How do I handle this?