Members of the LGBTQIA+ community are more likely to face mental health challenges. However, stigma and the fear of being outed often prevent them from seeking professional support. To address this, we collaborated with mental health professionals and LGBTQIA+ communities in Japan to develop a multi-user Virtual Reality (VR) platform that facilitates access to group therapy sessions. The system allows users to participate using personalized avatars and customized voices, preserving anonymity while enabling them to present themselves as they wish. We conducted a user study with 21 LGBTQIA+ participants and two qualified counselors to evaluate their experiences with VR-based therapy. Findings revealed that the created avatars enabled participants to express their chosen gender identity and increase confidence, acting as protective intermediaries. However, participants also noted how anonymity could affect trust, and suggested that better representation of body language and the introduction of trust-building activities could help compensate for such ambivalence. Overall, the platform fostered a strong sense of co-presence, and both counselors and LGBTQIA+ members felt that, with some ergonomic adjustment to improve the comfort of the headset during longer sessions, VR platforms could offer substantial opportunities for safe and representative access to mental health services.