((complic8d))
I also hold a lot of shame inside of me... And I don't believe it's possible to just say that it's not yours to own and get rid of it. I think it requires working through. It seems to me that the good news here is that you are working through already. Noticing your difficulty sharing and noticing the shame is there are two huge steps.
I really and truly understand how hard it is to discuss things with T. My guess is that you didn't have too many people validate what you were feeling when you were younger. At least that was my case. I do the same things as you. I write T letters and I write poetry and I read these things to him sometimes. I also have finally worked my way up to discussing certain things and saying them out loud. Yikes, it is hard, hard work.
I know you don't want to hear this but just keep on doing what you are doing. Take risks in therapy when you feel able to. Also, speak to T about these feelings. Maybe you two can come up with some strategies together to make you feel more comfortable.