What's more important? Whether your Mom finds out, or you get to the point where your life works out the way you want it to? Your therapist won't tell your parents unless they ask, and then there is patient confidentiality to overcome, though I'm sure state laws differ. The therapist isn't probably going to contact your parents uninvited, that would require extra work -- that alone will stop your therapist from telling. But worry about your health first, not who knows about it. In the long run, who cares about that?