I just can't quit smoking!?

I smoke a pack and a half a day! My sinuses are killing me and I feel that I can't breath! I have tried to quit but I get extremely irritable and lah out at everyone, I also get really depressed, bloated like hell and extremely tired. I have tried excersising but I get so tired that I can't even get outvof bed! What can I do to lessen this so I can quit for good?