"I am an Optician, what your experiencing could be adaptation problems but your optician should be able to do some adjustments to the glasses that could make the adaptation easeir to bear. Sometimes just changing the angle of the glasses will aleviate alot of what you are experiencing. Sometimes new bifocal wearers cannot handle the full prescirption and need to ease into it. If it does not get better for you in a week then ask your eye doctor to recheck you and maybe your presciption can be altered to make your new glasses more wearable
One adjustment has already been made. This is the same problem I had 27 years ago( last time I wore glasses) After so many years of seeing things the way (size, shape ect) it is a hard adjustment. It is a psychological as well as a physical adjustment. It will happen. I have been instructed to wear them at least full time for the weekend to help. When my new contacts come in I will no longer be able to wear them to sleep in. I am angry that my eye doctor last time did not tell me that I was developing problems. My doc said that as progressed as my eye problem is he should have seen it .