Hi Jexa,
Your T sounds awesome. I'm really glad you had a good session and that things seem to be going better.

About the mental block - I think trying so hard to overcome it probably won't help it at all. Maybe instead you can try really hard to be patient with yourself, and trust that when you are ready and it is the right time, you will be able to work on the very difficult things.
I also think talking to T about the mental block might help dissolve those strong defenses that you feel are protecting you.

I also agree with Googley, that writing in between sessions can be very helpful. Have you ever tried stream of conciousness writing? It is when you write whatever comes to your head, even if it is nothing at all, but you just keep writing and don't stop. Once when I did it I couldn't think of anything to write, so I kept writing 'I dont know what to write', and after a few lines of this I started into a different topic that led to some pretty significant feelings and insights that I didn't even know I had.

oops - I'm sorry if this is so long and maybe I am way off base...just ignore me if I am.