
Hi Rachael,
All I can suggest is that you put a boot on his foot when you can't be there to stop him chewing it. Hopefully in a few days it will have grown enough to be clipped back a bit further. Maybe a painkiller will stop it being so sore and then he will be more likely to leave it alone. Try not to let him get into the habit of chewing/licking it, because it can be very hard to break them of this.
Hope it sorts out soon - I'm sure it's very uncormfortable for him.
:)