Countertransference happens when therapists project personal feelings onto clients. It can be harmful if not managed effectively, but can also be helpful if handled well. If you feel uncomfortable, it's okay to talk to your therapist about it.
Transference is when clients project past feelings onto therapists. Countertransference is when therapists react emotionally to clients’ projections. To maintain professionalism and objectivity, these should be managed using self-awareness, empathy, and setting effective boundaries.