I'm sorry to hear about this, I think that therapists really need to give us consistency. My thoughts are that your therapist should find a way to continue to give you two sessions, either by working late or coming in early one morning, or by not taking on this group at all. I think that they either forget or are ignorant to the power that therapy has to help or harm people, I think that your therapist should find a way to continue seeing you twice a week to prevent any harm coming to you.