When do you see your T again? Maybe print out what you typed here and bring it with you. You seem to convey your despair very well in writing, so showing what you wrote might help your T to understand more. Or maybe call or e-mail your T before your appointment if it's not for a while.

And I agree with Leah to try doing things to get out of your head. If you can't stop the thoughts, then try writing them all down. It helps me to write things out, even if you don't show anyone.