So sorry you're having this problem. I had open wounds for months, too, and thought my left nipple would come off for sure (it didn't, thank goodness).
In my case, whatever the problem was that caused the damage initially was long gone, and it was just a matter of getting the wounds to close (though I wasn't sure of that till they finally healed). The number one thing that saved me -- and my nipple -- was wearing wool breast pads round the clock. www.danishwool.com
is where I got mine. About a week after I got these, I could see that the wounds were starting to grow closed at last.
APNO did not work for me, either. I'd advise you to discontinue using it: if it were going to work, it would have helped a long time ago. I switched instead a combination of Neosporin and hydrocortisone creams -- a dot of each mixed in the palm of your hand -- after each feeding. You can just wipe off any visible excess before you nurse again. For some reason this really worked, even though APNO didn't work at all.
Once they finally started healing, the wounds, which were large and sort of circular, took 2-3 weeks to totally close up. And where they were I now have thick purple scars and funny-shaped nipples. But I also have a pain-free, non-gory BF relationship, and I was sure I'd have the damage the whole time we nursed, until she weaned and I could get stitches. So it is possible to heal! It will get better!
I wish you all the best! Try the Neosporin/hydrocortisone/wool pads combo. I hope this helps! Feel free to PM me.