I suspect that B12 level was not in the US? Is that correct?

I have to know before I convert it to US units.

If you can't post all the ingredients... What is the B12 dose in that supplement? Is it cyanocobalamin?

Is this your product?
http://www.nationalnutrition.ca/detail.aspx?ID=3746

Without details as to what type of B12, I would assume it is cyano. 75mcg is not much. This is a Canadian product, so converting to US units....your B12 which is probably pmol/L:
We have a subforum here that explains many things. Also our sticky threads at the top of the first index page on PN have many links and lots of information too.

pg/ml=318 pg/ml Which is low but not alarmingly low.
235 divided by conversion factor .738

Ranges have changed about 10 yrs ago in US medicine. It is not an alternative thing, either.
I see where you are the ranges are very low, and still reported as "normal".
Here is a 2003 medical site for doctors to learn the new protocols in US:
http://www.aafp.org/afp/2003/0301/p979.html

So I think your first thing to do is get methylcobalamin and start with oral 5mg daily on an empty stomach, for 3 months, and get retested. iherb.com ships to Canada and has several suppliers including Jarrow which is in Canada.

You should get that level up to at least 1000 US units or 738 pmol/L in Canada. Low B12 is very damaging to nerves.

I still would like to know if you used any drugs in the past that are known PN triggers. Fluoroquinolone antibiotics or Flagyl, or Macrodantin. Two of them are used for bladder infections. The Flagyl (metronidazole) is used for vaginal trichomoniasis, which may have been tried in the past due to your pelvic symptoms and endometriosis. The fluoroquinolones like Cipro cause nerve damage which is thought to be permanent, at this time, and can have been anytime therefore in the past.
Macrodantin PN would possibly reverse in 2 yrs or so, in some patients.

Magnesium supplements are also very helpful for PN.
This is my magnesium thread:
http://neurotalk.psychcentral.com/thread1138.html
Aim for 1/2 the RDA for now, and that would be around 200mg a day elemental. Avoid oxide form, as it is not absorbed.

There are over 100 causes of PN... your first attention should be to the most common causes, and fixing any nutrient lows that may be causative.