VG will certainly help, but you may need a lot of it to really reduce that sharpness, which in turn will cut the nic considerably. Then you may be back to trying to balance the flavors once again.
I have some pistachio flavoring that is OMG strong, and started out with a 6ml bottle and it turned into a 30ml mix once I was done trying to get it right.
If the batch was small enough, it may be worth mixing up a new batch with less flavoring, then perhaps add some of your sharper liquid to it to get the results that you want.