It took me a couple of years before I could 'cry' in front of my Ex T, and even then it was just the odd silent tear trickling down my cheek. It took another couple for me to feel safe enough to actually let those silent tears actually come more than that. Unlike you, it never seemed to bother me that I couldn't do it, but I think I know how you feel because I have similar intense frustration about other things. And the only advice I have is time, and talking about it, I'm afraid. But you said you had done both, so I'm not sure I've much else to offer, though I wish I did.
I fully cried once in front of my Ex T, right near the end of our work together. Coincidentally it was the session before she dropped the bomb shell that she was stopping work immediately. That was five years after we started working together. I turned away from her and she came and sat next to me, held me in her arms and it all just came. Heaving sobs, noise and all.

The only reason I mention it is because we had learnt over the years that touch was what allowed my emotions to come out. I know it is frowned upon and I know a lot of therapists don't allow it, but safe touch was what allowed me tears to come to the fore, as she would take my hand or allow me to rest my head on her shoulder. Something about it allowed me to really open up, to her and to myself, in ways I could not have otherwise.

But I don't know if that is possible in the work that you are doing.

Ps, I never used to cry at all, either, but now I find myself welling up to movies or sad stories or songs. The emotional defence wall has been softened, it seems!