Dealing with the Infantry Peril

[PPoS]

Hi, I'm playing a Long Campaign as the Japanese, starting in 1931. I've had major successes against the Nationalist Chinese forces during my first two engagements (two Decisive Victories).
Now I'm on the third engagement and have encountered a quite "hairy" situation. My force consists of 2 Infantry Companies and have an assortment of tanks and artillery in support.

My dear enemy, Nationalist China, seems to have atleast twice the number of Infantry Companies that I have.

1st Company is holding the right flank and together with elements of the 2nd Company; the center flank. The right flank is apparently where the main enemy attack takes place; hordes of enemy infantry. I've been trying to hold my ground, but the 1st Company's 1st and 2nd Platoons have almost been destroyed (desperately trying to hold their ground).

At the same time there seems to be another enemy company attacking between my center and left flank (taking out one of my platoons), so I don't really have any other forces to commit to the right flank.

Are there any great tactical advice on how to deal with this situation? And how do you really handle massive hordes of infantry attacking?