Does your SO push you away?

My SO seems to always emotionally push me away every time he has a bad day/is having family problems. I have consistently told him that I am always here for him and that I am on his side. I don't like to see him hurting or in a bad mood but I don't know what to do when he completely shuts down on me. 
I try to give him space, and do nice things for him, but it never seems like it is enough for him. 
Advice please?!?