Headaches

I am 26 years old, had a VP shunt placed 2 years ago while I was 4 months pregnant, due to a glioma between my 3rd and 4th ventricles.  Since the shunt was placed I have had severe headaches daily.  They gave me codine at first, then after about a year that no longer worked.  My family doctor tried a variety of medicines for migranes (migraines) ie anti-depressants, bloodpressure meds and NSAIDS.. none worked. They started me on Lore tabs ~10 months ago. I am now pregnant again and have been to the ER twice in a week for severe headaches with vomiting. The Lore tabs were no longer working so the doctors have now given me oxycodone.  It works for the pain but my neurologist says that some of my pain is withdrawl (withdrawal) from hyrdocodone.  My ventricles are never enlarged when I get scanned so my neurosurgeon doesn't want to do anything about the shunt.  I am tired of being in pain and more tired of taking pain meds, expecially while I'm pregnant.  Should I get a 2nd opinion from a different neurologist or try to wait this out a little longer?  Wouldn't the oxycodone make the effects of the hydrocodone withdrawl (withdrawal) not as bad?