Why does my boyfriend get angry like this?

Ok so my boyfriend came home and i told him his powerboard stopped working.. and he starts to question me like "what did you do to it?" "it was a $100 power board" and was really angry... i said i dont know it just stopped working.. he pulled it out of the wall angrily while i had the telly on to have a look at it in a rutt.. he endded up fixing it.. then he went to fix his bike so i went to see him out side. I noticed my car wasnt in the driveway so i asked him where it is. he said its broken down, down the street. he's been using my car to get to work coz his bike has a flat tire.. so then he calls his dad up to pick him up and get a new tire from the shop. I asked him for a hug before he left and he got angry saying i've been angry all day.. i said no i havent i was just annoyed at you getting angry at me over the powerboard. He said he was just stressed because my cars not working and he needs to fix his bike to get to work tomorrow. I said thats fine but you dont need to blame me and get angry at me for it... Then he storms off angrily and said "Im not blaming you, you stupid c word" Im so confused...