if hes only 3, have u bitted him properly when u started to break him in. it is normal to place the bit on the low side when first introducing it, so he can play with it and find the most comfortable place to hold it himself. when he accepts the bit, then raise it into the correct position. it should have 2 wrinkles on the lips which should "unwrinkle" if u pull down on the cheekpieces.
we usually ride younsgters on 2 reins at first, one attached to the bit, then the 2nd rein attched to the "dually headcollar" which he was started in. this might be helpful to you if u lose control when his tongue so over.
there are other options but as he is only 3 , id start from scratch again.