Everyone here really has to make their own decisions regarding drug therapies. I only provide information, that doctors might not know (or is being concealed by drug companies etc,)
As far as your personal experience, Elaine, I see several possibilities for you.

1) It is possible your PN was minor until you added the MacroBid.
All the papers I've see on nitrofurantoin as a PN trigger discuss a reversal with time, of the PN if it occurs. Yours has not done so.

2) Is is possible you have a additive effect or synergistic effect on the nerves with both high dose Lipitor and Macrobid. Typically the research is very thin and resolution from PN caused by statins is difficult to find anywhere. Dr. Graveline on his website does discuss his resolution of memory loss from Lipitor, but he was not on it as long as you.

3) You could try lowering your dose of Lipitor to see if you retain the numbers you want, at the lower doses. This is feasible. You could always go back on it if this fails with little if any harm done.
Both Dr. Graveline an Dr. Jay Cohen, suggest this treatment option for those with profound hereditary hyperlipidemia. Dr. Cohen has written a book discussing drug dosing in general and has suggested that drug companies arbitrarily choose a dose when lower doses may work. For example, Crestor now once or twice a week in a very low dose, does work for many patients.
There is a study on this.
http://www.jaycohenmd.com/safermedication.html

Two books by Dr. Cohen...
http://www.amazon.com/Over-Dose-Jay-...s=Jay+Cohen+MD
discusses medication overdosing

and:
http://www.amazon.com/about-Statin-D...s=Jay+Cohen+MD
Discusses alternative dosing for statins and other methods of approaching elevated cholesterol.

The statin drugs were designed initially for patients with familial hypercholesteremia (not for the general public). What we know today, about genetic variability in those who may potentially be damaged by them, is also fairly new. I think with all this new information, you could
try to lower that Lipitor dose. You will likely always need some statin, because of your genetic history but how much is a cloudier issue. These drugs were designed for you... but there may be wiggle room in the dosing which you won't know unless you try to find it.

The member olsen on PD forum knows much about the genetic variability and potential damage from statins. She works in the research field, and really is highly informed on these issues:
http://neurotalk.psychcentral.com/post1002533-6.html
You could be tested for that gene (SLCO1B1) she mentions in this post. And you could PM her and discuss things...she is very helpful and has access to more resources than I have.

4) you can accept your fate with your treatment as it is now. This is what you seem to be doing from what I read in your postings.
Keep in mind that the research does show, risk of hemorrhagic stroke is higher in statin users than those not taking it. And a bit lower for blood clot strokes. Also if one does not use CoQ-10...with time, statin users face a risk of heart failure due to heart muscle weakness/damage. And all the other negative potential effects also increase in patients 5+ yrs into treatment with statins. There is little if any evidence that CoQ-10 protects from nerve damage but it does help muscle side effects so far. It is possible with more time the CoQ-10 will show more
positive results. The new water soluble affordable forms, are going to take more time to show up in studies. CoQ-10 until very recently was poorly absorbed even in the oil gel caps.

Everyone is different and brings their own unique genetic profile
to the table where medicine is concerned. What one person needs will not necessarily be what the next person needs. It would be wonderful if medicine were more personally tailored, and perhaps soon, this will happen.