How does one become less self-centered?

I have a huge problem, and that is that I am very self obsessed. It is ruining my relationship with the sweetest, kindest, sexiest man in the world.
I want so badly to make him happy. I realize that it is not 100% my responsibility, and no one can MAKE you feel happy. Whenever it seems like he’s feeling something negative, I automatically assume that it is my fault. Especially since he is not a good communicator, and won’t ever tell me what is wrong. Then I get into this huge downward spiral of negative self talk and self loathing, and just end up weeping uncontrollably, which in turn makes him feel frustrated and upset.

I know that people are SUPPOSED to have emotions besides happiness, and that it is a healthy thing, I have difficulty not turning it into something that is all about me.

How can I stop doing this? It’s ruining my life, and his too.