I don't think spacing your sessions to 2 weeks will necessarily weaken the transference. It could. I usually get busy with my life during the 2 weeks but I still think about my T a lot.

Can you try talking about your Mom? I was in therapy for 3 months before my T realized my Mom died a few months before I started therapy. I never wanted to talk about her though I needed to. It was like pulling teeth. It took a few Ts before I could start grieving. If you talk about your Mom, probably weekly would be better. Every 2 weeks is hard if you're not ready for it. I hate it but have no choice. As far as when to quit therapy, I'm not the best person to answer that question!