Hi Amy,
I can really relate to this as my t has said similar things to me.

I know I left feeling bad about myself to.
Working through a plateau can bring about the best work; it can stir the emotions deep below because it challenges your surface feelings.
I ended up writing a letter to me t about therapy and how I wanted it to change, I also sent her a book to read to understand my illness (which she really liked) which propelled the therapy forward.
Sometimes it gets worse before it gets better.