I have such a fear of rejection/abandonment that your reaction to the letter makes perfect sense to me!!

This is one of the major issues I'm working on in T, I think. And his continual presence and patience is showing me over time that this time, I'm not going to be cast aside.

I did try writing down some things T has done that show how much he is there for me, so I could refer back to that list when I get fears like you described. It helps a little - but I think what helps the most is the passage of time in our relationship.