I hope you have a good enough connection with your mom to talk to her about this, because it seems like this is the only thing you can do since your mom is the one who makes decisions about your therapy and is in the position to solve problems if something goes wrong. Explain to her what's going on the best you can. May be it's just this particular therapist you don't feel comfortable with. May be there is something else going on. Talk to your mom. I hope she understands.