I wonder if this comes down to distrust as much as anything else.

You were thinking how great T is because she says/does certain things.

Then your mind jumped in with 'but hang on, she's not so good because she doesn't say/do this.'

Then you started to feel miserable about the relationship.

I recognise this pattern too.

The truth is, no relationship is perfect and the t relationship is one on its own, so there's nothing to compare it to. I think this is about trusting it for what it is.

T has made a decision not to talk about certain things. That is the nature of the relationship. If she talked to you about her private life she wouldn't be a very good t! It's not a rejection of you, if anything it shows she is protecting you. She knows that withholding information about herself means the focus remains on you. And that is the nature of the t relationship. It's how it should be.

Your thoughts may well intercept with criticisms when you try to feel good about something but try to catch this when it happens and remind yourself that what you felt good about just a minute ago still exists. If you find yourself believing a negative thought that makes you cry or feel angry or depressed, ask yourself whether your emotion is really justified. Is it that T doesn't care, or is she simply doing what a T should do? I bet you'll find it's the latter. If this is hard to believe, remind yourself of all the times that T has shown she does care about you. So that's evidence that she does. Anything else is the nature of the t relationship, which is to benefit you if even that doesn't seem the case now.