You're definitely not the only one - sometimes to urge or desire to cry is overwhelming and I feel like I want to sob but nothing comes out. It's like the feeling will occasionally bubble up but not quite break the surface.

I think paulswife1 has an interesting approach - any kind of "negative" emotion was always taken as a sign of loss of control in my family when I was growing up. Perhaps as a consequence it's very hard for me to give up control, let go and just feel.

I don't know if it helps but you are definitely not the only one