oooh poor little lad! Its horrible when their teeth hurt like that.
Ive tried various things when my son has had teething pains (luckily most came through with no bother) a few of them being.
Teetha natural teething granuals from chemist
bonjela
calpol when really bad and he has cold like symptoms with it
Frozen banana, whole, so that he cant choke on a lump
a gum massager for babies. Its like a toothbrush but has knobbly little rubber bits instead of bristles.
Obviously you cant give him a banana at night but there may be something in there to try.
I hope his teeth pop through soon with no more problems