L.U.
D. - Two things came to mind as I read your post.
#1 - is your son mentally okay? I mean does he have ADD, ADHD, or any other kind of mental imediment?
#2 - If he does NOT...then you need to STOP restraining him.
You said that this method is working, but it is not! He just bit you again, and he is still having freak outs!
When you see that he is getting ready to have a tantrum, put him in his room. What fun is a tantrum if no one is there to witness it? Do not go in his room, don't worry if he is throwing things (if he breaks a toy the toy is gone! Next time he wont break a toy) If you go in there when he is throwing things then he KNOWS.."Oh, I act naughty and mom gives me attention" Same thing with the "forced restraints". He knows that you will hug him to get him to calm down so he will act up waiting for you to physically restrain him.
You can put him in time out even if he is mad. It's okay for children to cry and scream as long as they are not moving from the time out spot. If he get up, you put him back. It's a battle of wills mama, and if you do not put your foot down NOW and show him that you are boss, it is just going to get worse.
He is old enough to calm himself down. My son is 3 also, and when he gets mad at me he goes to his room, closes the door and then has his fit. It usually lasts less than a minute. There is no one there to watch it. He calms himself down by himself! Your son can do it too.
Also, you mentioned that he hurts himself with his tantrums. Some moms may not agree with me, and that's okay. But most children don't like to be hurt. He will notice if he is flinging himself around and hurts himself that that is not all that fun, and he will learn (by himself) to throw less vioent tantrums.
You mentioned that you are living in a house with 5 adults. That's a lot. He probably does not get your undivited attention very often, so he resorts to tantrums to get it. Put aside some "cuddle time" every day with your son. Read books, sing songs, talk about when you were pregnant with him...jsut some uninterupted time with you.
Good Luck, L.