Help my TB won't take a bit!

First check his teeth, check the bit and I wouldnt have 3 people out there trying to cram the bit into his mouth.  If it is that hard to get in where it never was before then he is trying to tell you that something is terribly wrong. 
 
It could be that he realizes that the bit means getting rode too. After you rule out teeth and saddle fit problem, I would start with the lead rope and take it up over his ears just like a bridle.  Could be that he has a sore in his ear that he doesn't want touched by the passing bridle.  Go out and practice with the lead rope just like it was a bridle.  Do it over and over.  When he gets relaxed and lowers his head then begin placing your thumb in the corner of his mouth each time just until he opens his mouth.  When that isn't a problem place the lead rope in his mouth several times to show him that you won't bang his teeth and htat there is no pain.
 
Then and only then would I move on to the bridle.  Even then I would just put it on and take it off several times being very careful not to hit his teeth.  Maybe go back to the snaffle for a while and do some flexing and softening excersises.  But I would definatly check his teeth.

I've done all but have the vet check his teeth. He is not sore he doesn't want me to ride. I have looked at his teeth and had a friends mom look at them -she has grown up with horses and still has them-

Sounds like you need to start over with bitting.
 
I have a friend who has ridden horses almost as long as I have, and he's still not very good at bitting his horses. He's half scared, and they catch wind of that. Also some horses will get that way if their teeth get bonked when you're bitting or un-bitting them.
 
You need your horse to get used to putting his head down for you. Until he's doing that no problem, I don't think you should be trying to get a bit in his mouth. Maybe it's time to back up a little and relax.
 
I don't think I'd choose 3 ppl and a stud chain to fix this problem.

He is doing better now but its like he was mad at me for not messing with him. I didn't do anything but feed him for bout a week so i could hang with friends. I didn't explain the whole thing very well. He is so tall he lefts his head up and nobody can reach it, so lisa had a hold of the rope to keep his head low, lauran was holding the bridle , and i put the bit in his mouth.Its not like we beat him.