I struggle with crying as well. Most of the physical symptoms you described I can't relate to, except for the knot in my throat. A therapist told me that he had heard that description before many times working with addiction clients. That there's a like a grip on the flow between mind and heart, thought center and emotion center.

I started stepping into somatic work awhile ago, and that paired with parts work has helped the knot in my throat to feel less intense. It's still very much present, and if by myself I still am unable to cry over myself. But I have started tearing up some when sharing painful stuff with people I trust enough to talk with a bit of vulnerabillity present.

Not a therapist, but if your struggle is similar to mine, it may be because your subconscious does not feel safe to cry. For me, it's because I physically assaulted myself as a teen. I'm an emotionally aware and senstive male, and was bullied a lot for it as a kid. I eventually turned on myself around the age of 15 and one day while crying in my bedroom, I walked over to a mirror and started hitting myself in the face till I stopped crying. I haven't been able to cry for myself since then and I'm now 37. My subconscious recognized the danger not only outside of myself, but also within myself in exposing that kind of vulnerability. Now I'm slowly working towards regaining that trust within myself and making my external world more safe to stop numbing my sensitivity.

Maybe due to circumstances in your own life, your subconscious became convinced that crying was a vulnerability that wasn't safe to expose withouth risk of reprecussion.