Help, dog has foul body odor, scratching excessively, chewing, what to do?!?

So recently my dog has gotten fleas from an outdoor cat that comes by my house and eats cat food. I've washed him with flea shampoo, did flea dip, used advantix on him, shampooed him with regular dog shampoo, and he still smells very terrible! The odor seems to be coming from his body and is so strong I can... show more So recently my dog has gotten fleas from an outdoor cat that comes by my house and eats cat food. I've washed him with flea shampoo, did flea dip, used advantix on him, shampooed him with regular dog shampoo, and he still smells very terrible! The odor seems to be coming from his body and is so strong I can smell it from the other room, even after he has left the room it still smells where he sat. Smell lingers when he walks by. He usually sleeps under my bed and even though I have sprayed the area with febreeze and other things over and over, the stench is still there. The fleas seem to still be there because he is constantly scratching and chewing at his legs and back and such. I have also noticed that some small pieces of his hair have fallen out and are all over in different areas on my floor. I dont see any missing patches of hair on his body though. He started to smell badly when I noticed that my other cat(one that is indoor) was scratching and when he began scratching. I also bombed the house to get rid of fleas and washed the two cats, they seem to be fine. The dog is the only one still scratching. Does anyone know what to do? The smell is so bad i have to get him in the other room and close my bedroom door so he cant get in, just so i can sleep. The smell is so horrible! Please help!
Update: All other members in family smell the odor as well. Had dog for years first time this has ever happened. Its not me that stinks! Haha.
Update 2: Dont answer unless you seriously know what to say please. This is a serious thing and I really need to know what to do. Has anyone had this happen to a pet before?
Update 3: The dog is male. And a little older. Dont know how old exactly he was a stray before and was not a puppy when i first got him.had him for atleast 7 years or so
Update 4: Before I started washing him and etc he started to smell very bad. Thankyou for the answers so far! =) thankyou thankyou.
only one flea dip, advantix 3 days after
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