first you have to find out what is wrong.
what is he mad about.
sit him down and ask him what he hates (hate is a strong word, use
'dislike' if u may) about you or your relationship. and then ask
him what he loves about you.
work on it.
for example, I hate how child-like my bf acts at times. and i told
him, he's working on it.
communication is key
good luck and keep us posted.