I'm so sorry, Tears.
I think it was a strong and loving thing that your Mom did, by the way. She didn't make a scene or take the easy way out and pretend not to notice, but discreetly and unequivocally told you what you probably already suspected.
So in all of this, that's one thing to be thankful for. If it helps to think of it that way.
I can really feel the heartache in your post and I know that sinking feeling so well.
I hope you find some support for yourself.