i finally told my adopted mother she is not my mother and i'm not her son

You won't distinguish a foster mom from real mom unless you were told of it. When it is revealed, in most cases the respectful fond love to the mom is only multiplied, wanting to hug and kiss his mom more dearly.

What do you think it might have done to her?
You are not the only one who has feelings

How did you find out first?

Very sad

How on earth can anyone be so ungrateful?

Sounds like an ungrateful child who is trolling us.